Forensics Notes

Forensics Review: Chapter 1: Introduction     Forensics- “Before the Court” in Latin. Forensics means that an individual is an expert in their field and is therefore qualified to give testimony before the court. A person becomes an expert by publishing, studying and researching. One’s research must then be accepted as true- you need to be able to prove the things you claim. The Scientific Method: - Notice a problem- there’s no reason to question something if you don’t see a problem - Do research- has anyone researched this before? - Form a hypothesis- “If than Then” - Conduct a controlled experiment- your experiment will have two groups, one control group and one experimental group. The control group is used for comparison, everything about the control group and the experimental group has to be the same except for what you are testing. The thing you are testing will happen in the experimental group and the control group is used to compare. Forensic History: - 1st fingerprints/palm-prints are found in cave paintings - Chinese seals- thumbprints in clay or wax - 1,000 AD- bloody footprints are used to convict someone of a crime in Rome - 1,248 AD- Chinese book is published showing the difference between choking, strangulation and drowning - 1400- autopsies are being performed in Europe - 1784- London, first murder conviction from physical evidence - 1800- first crime lab, Lyon, France o Edward Locard, theory of transference: whenever two materials come into contact with one another, there is exchange of materials between them. - Late 1800’s- first fingerprint labs in Argentina - 1887- Sherlock Holmes, introduced new ideas like blood typing. He was not the first fictional detective. Mark Twain was the first to have a detective use fingerprint analysis to find a suspect - 1923- first forensic lab in the US- Los Angeles, California - 1920’s- invention of the polygraph, cannot be used in court Forensic Fields of Discipline: - Forensic computing - Ballistics - Forensic chemistry - Odontology - Pathology - Toxicology - Serology - Forensic anthropology - Document analysis    - Linguistics Many documents presented to the court as evidence must have a forensic witness to analyze and interpret them Frey V USA- any new technology is welcomed in court once researchers are able to prove its reliability outside of court- this case was used to see if polygraphs could be used in court, which they cannot White coat effect- when you see doctors, you heart rate, BP… is different than normal because you are nervous about being by the doctor. Therefore, before doing a polygraph, the person is asked a lot of different questions in order to see how the body reacts. Chapter 2: The Crime Scene     The crime scene should be thought of like an archeological scene- the crime scene provides a window of what happened at that place during a specific time. Steps must be taken to ensure that the scene remains as uncontaminated as possible The crime Scene: 1) Starts with a crime 2) First responder- isn’t an expert. It is usually a cop on patrol, he can be dispatched to the scene, stumble upon it or be asked by a victim/witness for help. 3) Once aware that there is a crime scene, the first responder must keep a running log. The log may start as a visual or auditory log but must eventually be transcribed. The log is used as evidence and can only be transcribed on white or yellow legal paper with black or blue ink. 4) The first responder must determine if it is an active crime- are there injured, weapons, a second crime scene? 5) 2 main tasks of the first responders: making sure the scene is safe and secure. 6) Personal safety- starts even before a cop is sworn in- get vaccinated. Cops should keep personal protective gear in their squad car. Arrival at the scene: 1) Be aware of everything- smells, people coming and going, the time of day- lighting, environmental factors- indoor/outdoor, number of exits/entrances 2) First thing to consider- are there any injured. Always treat the injured victims first, even if you don’t know if they’re the victim a. Saving an injured party involves messing with evidence- for example, blood spatter and patterns can be disrupted- this is a downside but saving a person is more important 3) Call for backup once you feel the scene is inactive, safe and secure 4) Secure the scene- yellow crime scene tape. Always extend the area you secure- secure the biggest area possible. If you don’t have yellow tape, appoint other cops to watch the scene, use the squad car to block off the scene, use trafÏc cones or highway flares. 5) In the area, designate and exit and an entrance- keep a running log of everyone who is there- names, why, time in and out 6) The first responders job is not to collect physical evidence- he secures it for experts   7) His job includes dealing with the crowd- friends, relatives, press, politicians…. No one is allowed on the scene. 8) Monitor the crowd- are there any suspects, witnesses or victims that you need to find The Miranda Rights: - Suspects, witnesses and victims need to be read the Miranda Rights. - They stem from the first amendment- they have to prove guilt; you don’t have to say anything to help them do that o Right to remain silent o Right to a lawyer o Rights can be used at anytime - Anything a person says before being read their rights is inadmissible in court. But, if there are any witnesses around to hear what they might have said, you can use that. - The Miranda Rights are there to protect the cop and the case - People need to respond and say that they understand their rights - People who don’t have to testify- spouse, medical/psychological doctors (school guidance counselor is included), spiritual guides The lead detective: - The size and makeup of the lead detective and his team depends on the crime and the size of the force. 1) First job is to debrief the first responder. If there were people who came after the first responder, they will be debriefed too. Detectives may ask first responders to remain on site if needed 2) Initial walk through- first looks for evidence. They want to highlight all the important evidence and the most fragile evidence. Fragile evidence might not be super important. As they walk through, they need a system to categorize, mark and locate evidence- how will you be able to reference the evidence in the future? 3) Extending the search for more evidence- the search pattern depends on the crime. Is it indoor/outdoor, how much man power do you have, how long have you been disrupting daily life? a. Spiral search- one person b. Strip pattern- 2 ofÏcers c. Grid search- a lot of man power d. Wheel search- several people 4) Recording evidence- photograph everything with every type of lens, in every type of light, from every angle and then sketch the scene too a. Film V Digital- film is a piece of plastic coated in silver on the inside of the camera. Light enters the camera shutter, goes up and light hits the film. Where light hits, the film turns black and where it doesn’t the film turns white= a negative print. Film is then taken into a dark room and developed. Film has atomic sized pixels which can be extremely magnified and still remain clear. b. The first digital cameras were not clear and pictures can be photo-shopped but they are essential. c. You can take pictures with x-rays, sonograms, take pics of heat left behind, pics in ultraviolet, in radar etc. d. Even with all the photos, a sketch of the scene is required. Sketches add to the overall picture and beings together many factors. A rough sketch is done at the scene of the crime and a final sketch is presented at court- there can be no significant changes between the rough sketch and the final sketch. 5) The sketcha. Needs directions- north does not always point up b. Measurements- include a meter or yard stick c. Must be 2-3 static points that are permanent- record where the DB is in relation to the static points d. The surrounding are- roads, elevation, landscape 6) Individual evidence a. Fluids- blood, saliva, urine, sweat, semen- these are all fragile and need to be dealt with first, especially outdoors i. Moist samples are collected using Q-tips or cotton swabs. ii. Dry samples are collected using Q-tips or cotton swabs but they are moistened using distilled H20- water as free as impurities as possible iii. Any human fluids (unless directly taken from a body) must first be air dried before being shipped to a lab. The samples are then packaged in paper. This is done to prevent the contamination of DNA at all costs. Ai dried to prevent mold from growing on the sample, packaged in paper because the paper will breathe and not allow moisture to growmicrobes, viruses, germs, bacteria and mold can all infect samples b. Glass i. 2 types: known- found at the crime scene and unknown- carried away from the scene. The jagged edges of broken glass allow tiny fragments to latch onto clothes, skin and hair. Because of the way glass shatters, you can try and match up unknown glass with known glass ii. Glass must be shipped in hard plastic containers with one piece of glass per container. c. Weapons i. No better evidence than the weapon used in the crime. ii. First question- is it loaded? If yes, ammo must be removed. This is one of the few times evidence can be changed. iii. Each bullet, wherever it is found, is handled separately because bullets are made of lead which is very soft- you touch and can make scratched and dents iv. Bullets are shipped in plastic containers- you don’t want it to lose its shape or become damaged d. Arson samples i. VOC- volatile organic compounds- used to fuel fires ii. All VOC’s need to be collected once the fire is out. you can test to see what kind of accelerant was used- alcohol, paint thinner, gas/oil- the odors must be maintained. iii. Sealed metal cans are used to package arson evidence e. Hair samples i. Difference between hair that is pulled out and cut off. If hair follicles are attached, DNA is included ii. Hair follicles include nuclear DNA- DNA that has your 46 chromosomes iii. Hair shafts- hair will in case any drugs or alcohol you use until you grow it out and cut it f. DNA i. Mitochondrial DNA- only maternal, lasts a long time and can be used to trace people who live today ii. DNA samples must be taken the most seriously- DNA is 100% individual characteristics  2 types of evidence o Individual characteristics- can 100% be matched to its source  DNA- hair, blood, fluid, saliva, can all provide DNA, can be found anywhere  Prints  Bullets- are better than DNA or prints o Class characteristics- can be traced back to a specific group  These make up the circumstantial evidence- shirt work, footprints, etc. o Standard Reference Samples- not connected to the actual crime but must be collected for comparison  The murder scene o Homicide- the killing of a human being o Every unexplained death is considered a homicide until proven otherwise o Low brain function= death o The investigation of an unexplained death is under the control of: Coroner, pathologist, ME.  Determining time of death o Algor Mortis- the temp of the body- under normal circumstances, the body will cool 1.5 degrees F per hour. Environmental factors can effect this o Rigor Mortis- blood settles due to gravity- when it settles, will take on a blue/black color due to lack of oxygen. Tell us: how long the person was dead and of the position of the body changed after death o Bug eating- different insects will invade a dead body. We know the life cycles of these bugs and that can approximate TOD - It is the job of the ME to take charge of the body for either autopsy or returning it to the family- he/she will decide what needs to be done  ID of body o Begin with a wallet o Ask a witness for ID o Dental records o Prints o DNA o Missing persons reports o Tattoos, scars, metal (surgical metal has serial numbers)  o  o Jewelry Skeletal remains o Always treated as a homicide o Cold case- murder has no statute of limitations  How long has the skeleton been buried?  Carbon dating- for every 5,700 years the amount of C14 will be cut in half  Determine if remains are human  Any evidence of trauma- cause to think death is suspicious ID skeletal remains o Gender- size of hips o Age- size of skull, length of long bones o Race- skill, eye orbits, nasal opening o Profession o Physical appearance How evidence is examined - Before evidence is even examined, a running record of all evidence, in detail, must be kept - Chain of custody- evidence must not change from the way it was on scene until it reaches court unless for testing. Who touches the evidence, when they touch it, where it goes, what is tested etc. must be included on a chain of custody form. - Chain of custody must always be maintained Chemistry:    Quantitative analysis- physical- weight, shape, color, mass, volume, density Qualitative analysis- what is made of- its chemistry The universe: - The universe is made up of two things which is what chemistry deals with - Energy - Matter: defined as mass and volume. Weight=gravitational force which isn’t constant while weight is. MASS IS CONSTANT. - Volume- how much stuff can fit into a space - Density- mass/volume - Matter must have mass and take up space- volume - 2 types of matter: o Substances- pure; they have definite characteristics and a definite formula  Elements- atom is the smallest part  Compounds- molecule is the smallest part, made up of two or more elements o Mixture- no definite formula or traits  Cops like mixtures more than substances, they are harder to analyze but give much more information Air, water, body fluids, food, fibers…are all mixtures  The periodic table o Metals, non-metals and noble gasses o Metals- solid, gray/silver in color, conduct heat and electricity when they react, give electrons away o Non-metals- many shapes and colors, don’t conduct heat or electricity and will take electrons o Number of electrons can be seen according to line o Top number of an element= atomic number. The atomic number is the most important part, it’s the fingerprint of an element o The atomic number also equals the number of protons and electrons in the element o The bottom number is the atomic mass o Neutrons= protons/electrons – the atomic mass o The number of protons always equals the number of electrons in naturally occurring elements which gives it a charge of 0. o The smallest atom has the same properties as a ton of the same element. o Elements are substances- pure with definite characteristics and a definite formula o Isotopes- when there is one element that has the same number of protons and electrons but not the same number of neutrons- different atomic mass o Octet Rule- all elements want to have 8 electrons on their outer ring. To achieve 8 electrons, elements will bond together in order to achieve 8 outer electrons  Bonds:  Covalent Bonds- elements share electrons. Strong bond.  Ionic- share electrons- give and take, weaker bond. o When an element gets rid of an electron, they have a + charge, when they receive and electron, they have a – charge  o  Energy: Most energy people come into contact with has such long wavelengths that they can’t mess up the things you want to stay whole- like DNA. Energy moves in electromagnetic waves. All waves travel in vacuums at 186,000 miles/second. Wavelength – the distance between waves Frequency- the number of waves Long wavelength= low frequency= less dangerous High frequency= short wavelength= more dangerous o The smaller a wave, the more info you can get out of it  The electromagnetic spectrum:  Gamma ray- most dangerous, what makes up atomic bombs.  X-ray- 2nd most penetrating or revealing. X-rays can both cause and cure cancer  Ultra-violet- tanning rays, can do damage but is skin deep, can’t penetrate  Visible light- light used to see, used in microscopes. Light is made from a spectrum of colors ROY G BIV. Violet has the shortest wavelength and red the longest  Infra-red- heat- used to look at body heat, red rays  Microwaves- unique ability to vibrate the bonds of water, vibrate not break, which causes kinetic energy which causes heat to generate  TV and radio waves- radio waves are the longest waves, non-penetrating- don’t cause any harm. o o o o o Blood:      4.6- 6 quarts of blood in the body 7-8% of normal body weight Two main ingredients Half is plasma, half is living cells Plasma- the water and minerals. Dissolves nutrients, hormones and waste. Because plasma doesn’t have antigens, it can be given to people at emergency scenes. Living cells: 3 types  Red o No nucleus, not good for DNA testing o Spleen/liver recycle their minerals o Created in the bone marrow o Job is to transport cells for respiration o RBC need Fe (iron) for hemoglobin which is what grabs onto oxygen o Anemia- lack of RBC, more common in women than men o RBC’s are used to check for intent blood at a crime scene, when testing, they test for Contains hemoglobin ( which has Iron) which is very hard to conceal and get rid of  White o Have nuclei o Made in bone marrow o Able to eat up invading germs, usually not viruses which are harder for WBC’s to fight o Increase with infection; leukemia is an imbalance of WBC’s Platelets lnucrnr o Very small o Help with clotÝng Blood and blood types are class characteristics. Blood can be used to determine if someone should be included as a suspect or not On the membrane of blood cells there are protein markers that are genetic. They are called antigens Antigens- something that can harm you- germs, viruses, allergies…. Antibodies are made by the body to combat these things. Sometimes antibodies can do too much and will end up being harmful Before people knew all the properties of blood, they would give blood transfusions without a thought about blood type which led to death. In the 1900’s they discovered that there were different types of blood: A, B, AB & O. Rejection- occurs when the blood being transfused into a body does not match the blood the person already has. Type O blood- has no markers. Therefore, it is known as the “universal donor” O- blood can be given to anyone regardless of blood type. Type O blood is the most common type of blood. Type AB blood is the rarest of the blood groups. It is known as the “universal recipient” because it can pair with A, B and O blood types.          mitocGenetics: Why is our DNA 100% unique? Why and how does every cell in our body have the same DNA?         Gregor Mendel- father of genetics. He was a monk who lived in a monastery. His job was to take care of the gardens. While doing this, he realized that the plants turned out differently each season; he wanted to know why. He decided to study pea plants which have a life cycle of one season- good because he would quickly be able to see the characteristics of the plant. He was in control of his experiments- controlled the pollen, what went into each plant etc. After presenting his work the bishop, his work was hidden away. It was discovered years later and is still valid today. First law of genetics- law of dominance: the stronger trait will always win. o Capital letter= dominant o Lower case letter= recessive Punnett Squares- show the possible traits kids can have based on the genes of a the two parents The capital letter, when there is one, is always dominant A recessive trait. Parents can show the dominant trait while still being a carrier for a This explains how two parents with brown eyes can have a child with blue eyes. Aa Aa Phenotype- the appearance A Genotype- what’s in the gene Aa Aa Homogenous zygote- BB a A     Heterogeneous zygote- Bb A Homogenous recessive- bb- this is the only genetic type you can know from appearance. Blood types: A, B, AB, O; how can there be 4 different blood types that are all a dominant? Incomplete dominance- the offspring receives a blend of the parental traits. Red flower + white flower= pink flower. A+B= AB Mitosis and Meiosis   Mitosis o Asexual reproduction ( 1 Parent) o Two diploid cells are created into two new diploid cells o Creates exact copies o You get the second nucleus through DNA replication. The DNA strand is ripped apart by enzymes, then each piece of the strand finds a new complimentary base to pair up with. This leaves you with two identical DNA strands. You can now get two of the same cells with two of the same nuclei. Meiosis o Sexual reproduction ( 2 Parents) o lumCut the number of chromosomes in half o Re-arrange the genes o Creation of egg, sperm, sex cells, haploids, diploids and gametes o Meiosis occurs in the primary sex organs of a person- ovaries and testes o 50% of genes come from each parent o When doubling occurs, they trade genes, genes can cross over in a way that has unlimited results which is why every person’s DNA is different and unique. Every time a sex cell is made, the crossings are different even if it’s from the same egg or sperm. o Fertilization- 2 haploid cells, 1 egg and 1 sperm, come together to make one diploid cell which then has 46 unique chromosomes. This cell with its unique chromosomes is reproduced by mitosis- created identical copies of this unique cell over and over until it becomes a person. a AA Aa Aa aa     Reproduction o Each release of sperm is 3.5 millimeters. Each millimeter= 10-15 million sperm o 10-15 million sperm are released because there are a lot of barriers in a woman’s body which kills off sperm  Temperature- during ovulation, a woman’s temperature rises; sperm die at 98 degrees  Acidity rises  White cells- increase  Mucus covering organs increases o In the end, 6-12 sperm make it to the egg. The battle to create the best kid starts herethe sperm needs to be strong enough to make it to the egg. o 1 sperm +1 egg= 46 chromosomes= 1 baby o Fraternal twins- 2 eggs + 2 sperm= 2 eggs= 2 babies with completely different DNA o Identical twins- 1 sperm + 1 egg= 2 babies. The zygote splits so each have the same DNA. Identical twins need to be 2 boys or two girls- DNA is identical o Half identical twins- 1 egg+ 2 sperm= 2 babies that are half identical. Babies can be a girl and boy or two of each. o Usually when there are two zygotes, the body will reject the weaker one and keep the stronger one. Genetic engineering- taking genes from two different species in order to create something new. This take chance out of the equation. Through genetic engineering, scientists can create things like adrenaline, thyroxin and insulin. Other nucleic acids not used in the lab, RNA, difference between DNA and RNA is that dna contains sugar deoxyiribose and rna contains sugar ribose EXAM QUESTION- HOW DO MITOISIS AND MEOSIS CREATE A INDIVIDUAL CODE DNA Testing  In DNA testing, scientists test the non-sense codes of a person’s DNA Gel-electrophoresis- used to test DNA. Compare a person’s DNA to DNA found at a crime scene. The strands will be attracted to each other and pull together if they are the same. This test is 100% accurate because it tests the nonsense genes which are 100% unique to each person. Polymerase chain reactions- multiply DNA quickly without changing the DNA. This is used in labs when the DNA collected is too small to be tested. The polymerase multiplies the DNA so it can be tested. Polymerase doubles the amount of DNA every few minutes= millions of new cells. XX= Girl XY= Boy  Presumptive tests- immediately tell you if there is blood    Testing for Blood at a Crime Scene: Kastle-Meyers Test- tell you if there is blood by using chemicals to detect the presence of hemoglobin o Precipitin test- tell you if the blood is human o To find blood that is hidden or washed away Blue star and luminal- spray over large areas and hemoglobin will glow ( Pink = more hemoglobin ). These particles can make 1/6,000,000 of blood glow. However, can give false positives and false negatives. Darker color is positive for color test  Hemma stick- works like a PH test. Stick a swab in liquid, compare the color chart and see how much hemoglobin, if any, is present Definitive exams- further testing of blood must be done in labs o          Alcohol and Drugs: What is a drug? o Something that has an effect on body chemistry, the mind or both o Coffee is the most widely used drug in the world o Alcohol is the most abused drug in the world 4 major groups of drugs: o Narcotics o Depressant o Stimulant o Hallucinogen People take drugs to induce a feeling of well-being. Most people in prison are there in connection to a drug related offence. o Most murders due to alcohol and drugs o Most work lost due to alcohol o In domestic violence cases both parties are usually drunk or high o Child abuse is usually associated with alcohol o Rape- drugs and alcohol o 14 billion federal dollars are spent on drug treatment, 9 billion on law enforcement and 14 billion on prevention How do drugs work on the brain and body? o Our bodies contain neuro-transmitters; we are able to produce our own drugs naturally. On cells, there are small receptors, the body will produce chemicals, and when they attach to these receptors, a person feels happy, anxious, pain etc. o When a person takes drugs that are artificial, the body stops producing its own drugs. When you stop taking the artificial drugs, the body doesn’t realize it now needs to create its own drugs which is what leads to withdrawal- why people will do anything for their next fix.  Alcohol: Ethyl-alcohol: the compound that makes up alcohol Oldest form of alcohol is beer Alcohol is the result of anaerobic respiration by a microorganism called yeast The waste product of fermentation is co2 + alcohol       Any grain, fruit, vegetable with a starch, carbohydrate or sugar can become alcohol o Beer- 5-6% alcohol o Wine- 11-15% alcohol o Hard liquor- 40% alcohol Alcohol can be sparkling or still The % of alcohol is different in drinks like beer or wine because during fermentation, the co2 that the yeast releases kills off the yeast. Once the yeast dies, alcohol stops being made. The yeast dies at different times depending on the drink which is why alcohol levels vary Distillation- discovered on the Arabian Peninsula and was used to extract oils from plants. Distillation is how you can get alcohol with higher percentages of alcohol in them. o The process: alcohol and water are put in a metal can. Its then heated. Because alcohol and water have different boiling points, the alcohol boils first- all the first steam that is let out is from the alcohol. The steam is then cooled with cool water and what’s left is drops of alcohol.  This is how you can get alcohol with 40% rates  Moonshine- 100% alcohol Alcohol and the body: breaking alcohol down o B.A.C.- blood alcohol concentration/content o In the US, there a max levels set for flying, driving etc.  0.08- regular drivers  0.04- commercial drivers; trucks, cabs, delivery vans etc.  0%- for new drivers or anyone under 21 o Alcohol is a depressant; slows down body chemistry. It will cause reaction times to worsen and the effectiveness of your muscles will slow too. o Alcohol ingestion: there is no intake of alcohol into the blood until it reaches the stomach  Alcohol is first absorbed into the stomach. The amount that is absorbed can vary depending on things like what was in your stomach, what type of alcohol etc.  20% of the alcohol is absorbed into the stomach; it then enters the blood system.  The rest goes to the liver  One drink can be processed in 1 hour. By the second drink, the liver is already dealing with the alcohol from the first drink and therefore the alcohol just enters the blood- this raises your BAC above the legal limit.  With few exceptions, the body can handle 1 drink per hour Alcohol abuse statistics: o The leading cause of mental retardation in children is fetal alcohol syndrome (FAS) o 145 billion in wages are lost a year due to alcohol abuse o 40% of all murders and suicides include alcohol o 42% of all college students engage in binge drinking o 20% of college students are drunk each week o 50% of college students drink 2x a week o 60% of all college students reported violence in connection with alcohol o 40% of all alcoholics begin drinking before 15 years’ old           o A person is 4x more likely to become an alcoholic if they start drinking before 21 o The GABRA2 gene shows that there can be a possible genetic disposition to alcoholism Alcohol and its effect on the body: o Nerves- will de-generate, usually in the limbs, fingers and toes first o Throat- cancer increased risk; 40x more of a risk if you smoke also o Muscles- connective tissue will de-generate o Stomach- bleeding ulcers and stomach cancer o Intestines- chronic bowl syndrome o Bones- degeneration o Sex organs- men: lower testosterone, impotence and breast growth. Women- failure to ovulate o Pancreas- insulin production and digestive enzyme production will suffer o Liver- cir osis of liver spine or tissue o Brain- headaches, blackouts, increased dementia, actual IQ drops, seizures, tremors etc. B.A.C Effects: o .01-.06: well-being, relaxed, judgment and senses are already impaired o .06-.10: reflexes, depth perception and reasoning is impaired o .11-.20- slurred speech, anger- mood swings, reaction time decreases o .21-.29: stupor, blackouts, motor skills are gone o .30-.39- heart and breathing are impaired o Anything higher can and does usually lead to poisoning or death In the 1920’s, the first breathalyzer test was created. Since then, they have been proven to hold up in court. They have also become more reliable as time went on. It isn’t as accurate as drawing blood, but can be used in court One might think that a breathalyzer is a violation of the 5th amendment right- don’t have to incriminate oneself. Because of this, one can say no to a breathalyzer test. However, you will immediately be arrested and your license suspended. This is because when you sign for your license with DMV, the contract includes what will happen if you refuse a breathalyzer test. The breathalyzer tests works by measuring the amount of alcohol that you exhale. Just like you exhale co2, when there is alcohol in your body, that gets exhaled in the same way. GetÝng pulled over: At check points, you must follow instructions With a marked car, pull over when lights and sirens are signaling you to pull over Unmarked car- pull over somewhere public and well lit If your pulled over, there is usually a reason- can’t be puller over without cause When you get pulled over: o Roll down window o Have info easily accessible o Ask what you were doing wrong o Never say you were drinking o Never say you have alcohol in the car o Step out of the car- have the window down, hold onto the frame of the car- provides stability if you were drinking. Also, say as little as possible if draining              Field sobriety test: o Over 90% who fail will later test to be impaired o 3 portions 1) Nystagmus (eye jerk) test: using a light, finger or pencil to follow the involuntary jerking the eyeball does. With alcohol, the jerking will occur early and be more dramatic. This test is involuntary- you can’t control your eye movement 2) Walk and turn- walk in a straight line- listen to all instructions before staring 3) 1 leg stand and count- can you do 2 things at once? o If the cop feels you are drunk, they will give you a breathalyzer test. They have to do these 3 tests before giving a breathalyzer o If your refuse the breathalyzer, you will be arrested and license revoked. In addition, a court order will be gotten mandating a blood test to test alcohol levels. They can calculate what it would have been when you were pulled over Drugs: Weed, THC, pot and marijuana are all schedule 1 drugs- have the highest federal penalties The active ingredient is tetrahydroannabitol THC. Immediate physical effects of inhaling or eating: o Increase heart rate o Blood shot eyes o Dry mouth/ throat o Impaired reaction time o Short term memory loss o Possible anxiety/ panic attacks Marijuana is classified as a hallucinogen- causes perception to be altered Physical addiction is low but mental addiction can be high More cancer causing agents in marijuana smoke than in tobacco smoke When you smoke something, the temperature has to be very high- cooking the lungs; makes them leathery instead of elastic which makes them die. Marijuana and hemp cannabis are from the same plant; there is one species with many different varieties *every variety of marijuana is from the same species of plant Seed of the cannabis plant are thought to be one of the first cultivated plant seeds May be as old as 8,000 years old; used for animal feed, seed oil, fiber= rope Cannabis grown in cool dry climates produce very tough fibers and no THC Production of plants with higher THC levels: o Plants can have both female and male varieties or they can be both male and female o Marijuana comes in male and female forms o When the plant begins to flower, the male species are killed because they destroy THC o The female pot plant needs to devote all its energy to making THC not to making babies which is why the males are killed o Marijuana takes one season to grow; best in sun with rain Drug test times for marijuana: times can depend on variety, usage, activity and last usage Single use Urine 1-7 days Blood 12-24 hours Hair ------------- Saliva 10-24 hours Long term 7-100 days 2-7 days Months or years ---------------------- These tests search for the metabolic waste of the THC- COOH   k-2 spice synthetic weed- 100x more potent because of its unique ability to bind to brain receptors- all the side effects are also multiplied by 100- people die from it QAT/ KAT: chewed, mild hallucinogen effect, made in Yemen Hallucinogens:        Changes in perception Mood swings Effects neurotransmitters The chemical jump that brings a message from one neuro to the next is blocked. The message won’t be received or it will be messed up in either the brain or the muscles. The strongest is LSD They have more of a psychological dependence than a physical dependence o LSD:  Isolated in Switzerland by Doctor Hoffman  Found on Ergot mold- a common fungus  Legal in the US until the 1960’s  Flashbacks- physical or psychological. You can take LSD once, let it leave your system and randomly get high again without ingesting it again.  Short term effects: sweating, nausea, dry mouth, distortion of tome and spacewhy people take LSD o Magic mushrooms- psilocybin o Muscoline- peyote o PCP- angel dust; ingested, smoked, snorted. Violent, hostile behavior, confusion and paranoia o Salvia- pastoral, serene, magic mint, lahembra. Smoke,d chewed, made in tea People who use hallucinogens usually suffer from anxiety and depression when they stop Stimulants:   Oldest known stimulants are chocolate, coffee, tea and nicotine They all increase the nervous systems ability to work o Cocaine  Discovered in South America; the leaves were chewed  1862, German doctors isolated the active ingredient  Not a schedule one drug because it had medicinal uses o Crack cocaine- higher rush, more addictive, more risks o o o o o o Amphetamines- Adderall, Ritalin, concerta Meth- labs are dangerous to everyone around Ice- instant addict Amphetamines Speed Diet pills Depressants:   Used to be the most prescribed and abused drug Known as: sedatives, sleeping pills, tranquilizers, anti-anxiety meds o Valium o Xanax o Halcion o Ambien o Barbiturates- most powerful; when mixed with alcohol, breathing stops Opiates/ Narcotics:       All come from the poppy plant Used as sleeping or pain aids Highly addictive- physical and mental o Opium o Morphine o Heroin Synthetic forms o Vicodin o Oxycodone o OxyContin Microscopes: Compound light microscope o 2 lenses at any time in use o Was created in Europe in order to examine jewelry o Ocular piece- eye piece found on top, doesn’t change o Objective lens- there are 2, one high power one low power o Diaphragm- opens and shuts the amount of light let into the microscope; the smaller the hole, the clearer the image Stereo microscopes: o 10-15x Don’t use it to see atomical sizes, use it to see all the details on an object for comparison Focus- always begin with low power  Begin with the coarse lens= more cells that are smaller  Move to the high power/fine lens= fewer cells that are bigger When you examine something under a microscope, the objects are both upside down and backwards. L=7; d=p Electron microscope- used to look at GSR The microscope is one of the earliest forensic tools- made in the 1800’s o o       Firearms: The second amendment: “a well-regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed.” For a long time, this was the only gun law that America had. Two types of firearms: o Handguns and pistols  Require one hand to use  Revolvers- manual  Automatics  Most crimes use handguns o Rifles  Need two hands to use  Assault weapon  Automatic  Semi-automatic 3 parts to every gun: o The propellant- the explosive o The bullet- ammo o The tube- barrel Gunpowder:   Black powder o Earliest type o Discovered by the Chinese o Gave off a lot of smoke o Made of saltpeter, charcoal and sulfur o Black powder was also used in cannons Smokeless powder o Much more efÏcient o Discovered in France o Used today The Bullet:   Bullets were originally musket balls. They were round and made of lead. However, they were wildly inaccurate and needed a very close range in order to hit a target The modern bullet is made out of lead which is very easy to cast, melt and mold. Its parts include the bullet, gunpowder, primer, casing and firing pin The Barrel:      Smooth barrel- used in shotguns Rifled- used in all other weapons- what we use for bullet comparison The tube/barrel is made of solid steel. In rifling, there is a drill that goes through each tube creating striations in the tube that are individual and unique. A rifled barrel gives a spin to the bullet making it go straight Every time a bullet is fired, it will be 99.9% the same as the one that was fired before. The striations in the tube mark the bullet giving it a unique pattern. This is what is compared during bullet comparison tests Handguns:        Revolver 5-6 bullets Older variety of weapon Simpler Less expensive Larger ammo Don’t eject cartridge (casing) Rarely jam up         Automatic Greater fire power 18 bullets Smaller caliber More complex More expensive Ejects casing Can jam up Firing mechanism leaves a marking on the primer as it strikes which can also be traced Shotguns:         Smooth barrel- leaves no striations on the ammo No rifling marks The ammo is completely different- made of paper, plastic and cardboard Depending on the powder used, gunshot residue is traceable Kickback- after firing a shot, GSR can be found on skin, in hair, clothes, arms, face No casing= inaccurate Bullet Comparison: Bullets found at a crime scene must be individually collected, recorded and packaged. Packaging in a hard plastic container, one bullet per container. If the weapon isn’t recovered, the bullet can lead to the gun. Measure the size; millimeter and caliber of the bullet, determine if the ammo comes from a revolver or automatic          The gun, when found, can be test fired in to see if there is a match When doing a test firing, use either the same gun or the same type of gun. Use the same type of ammo. All you want to see are the marks made on the bullet made from the barrel. You shoot the bullet through cotton water and then compare that with the bullet found under a microscope. Comparison of: o The gun barrel- when rifled, will have either a left or right twist pattern o Compare the number of lands and grooves. The amount depends on the manufacturer o Find a distinct pattern to compare the bullets with o Even bullet fragments are okay for comparison. Bullet Wipe and GSR Before the bullet even enters the body, the bullet will leave bullet wipe/swipe on the first place that the bullet touches- clothes, skin, anything in the environment etc. Bullet wipe- the bullet carries all of the materials found in the gun, whatever it hits first, it will leave a circular, dark brown-black stain. This can tell you where everyone was when shots were fired, what the bullet hit first, if it hit anything before hitÝng the person etc. Gun Shot Residue (GSR)- the GSR that is removed from the bullet as it passes through flesh or fabric- it is only found on entrance wounds. Helps estimate shooting distance, length and diameter of barrel, type of bullet, type of powder used, type of material it passed through GSR is sometimes called discharge particles Blowback- the force of the shot will leave Entrance and Exit Wounds: Entrance Smaller More regular shape-oval Less bleeding Bullet wipe- large % No guts Almost 0 bullet fragments  Can tell angle of shot               Exit Larger Irregular shape More blood loss No bullet wipe Very little GSR Lots of guts Bullet fragments Can’t tell angel Biometrics:     Biometrics- the use of body parts to identify someone Fingerprints have been used by most countries for over 100 years; no two are alike, not even identical twins In most countries, fingerprint evidence makes up the majority of the documents presented to the court Before fingerprints, people used:   o Facial features o Scars/injuries o Tattoos o Branding 1870- Alphonese Bertillion devised a system of multiple body measurements. This system was used for 30 years; modern photography is much more useful 1891- Juan Vucetich- Argentina; first country to use fingerprints in a standardized way Prints:     Palm= hand Planar- foot Both palm and planar prints have friction ridges which are useful to grip, especially things that are wet How prints develop friction ridges: o Starts in utero at approx. the 10th week o The basal layer of dermis is continuously being pushed upwards. As this is happening, environmental factors in the womb create the individual print characteristics o Temp, salinity, pressure, finger sucking and touching all contribute to the way that friction ridges are formed. o Experiences in the womb are different for every single person, even identical twins, which is why everyone’s friction ridges are different o When old cells are lost, the new friction cells are in exactly the same pattern as the old ones. o Some repetitive jobs wear away prints, but the hand might still be identifiable o Some people are born without friction ridges and/or sweat glands NFJS and DPR Crime Scene Prints:       Visible- obvious prints Latent- hidden prints- needs to be dusted Plastic- looks 3-d, can be in blood, dry paint, anything sticky r All prints must be photographed first and then lifted Lifting a print: o Latent and visible prints are dusted o Prints on white backgrounds, use white or gray powder o Prints on black backgrounds use white powder o Cover the entire area with the powder. Then, brush away any excess dust, then take a photo of it. o Use tape to lift the print onto a permanent print card Known prints can be: o Inked   o Digital o Rolled- roll finger in ink, the roll on paper, one finger at a time o Flat- ink all fingers and put them down at the same time You can never take the same exact print 2x but 99.9% is good enough Print features: o Loops- 65-75%; most common o Arches- most rare o Whorls  Within the 3 main shapes, there are little minutea which identify the prints as being the same and unique.  To use print evidence, a forensic expert must present the evidence in court Trace Evidence:   Usually found in very small amounts; can be class or individual Hair: o The strand or shaft alone is a class characteristic- no one should be convicted from hair evidence alone. o Mitochondrial DNA can also be extracted from the hair shaft o Nuclear DNA is found at the bulb (root) of the hair o The forensic lab needs to determine:  Animal or human hair?  This is easy to do by looking at the outer cuticle  Once it’s a human hair, a comparison microscope is used to look at color, shape, length, dyed, bleaching  Can examine hair from scalp, legs, arms, nose, around the eyes o  Glass o o o o o   Paint o 3 groups of hair types:  Caucasian- medium, coarse texture. Straight/wavy, color varies. Pigment and gravels are usually fine and evenly spaced. Generally, found to have round or oval shape when cross sectioned.  African- usually curly, flattened circle when cross sectioned, very dense, pigment almost opaque, often spit along shaft  Asian - coarse, straight, circular when cross sectioned, thicker cuticles- medulla very wide, larger pigments and gravels During a crime or accident, microscopic glass fragments can end up almost anywhere; hair, clothes, shoes, ear, nose, skin The chemistry of glass varies greatly. The FBI database has 10,000 on record. Thickness, recipe density, refractive index… can help match up glass particles Every type of glass is on record by the manufacturer Glass should be packaged in hard plastic bottles Big pieces of glass should be placed in a box separated by cotton or any available material Hit and run tools- any top layer of paint is smeared off. However, sun can oxidize the paint which leads to more rust. Paint color could also have been changed, paint color could be different on different parts of the car o Every kind of paint has its own recipe- best to get from the manufacturer even though there are paint databases Impressions o Tires, footprints, shoe prints o Foot/shoe prints reveal a lot; shoe size, make of shoe, height, weight, gait o These prints are always photographed first o After, a permanent cast of each print is made o Footwear and tires are class characteristics but individual use can make them almost like individual ones