Forensic Science Short Answer Review

1) How many bones does the average adult human body have? 2) What is the name of the computer program created in 1986 that helps determine height, ancestry and sex of human remains based on metric analyses of the bones? 3) Why are infants born with fontanelles? 4) An age estimate can't be made on adults over the age of 21 using only the teeth.

1) 206 2) FORDISC 3) To accommodate the birth process and rapid brain growth. 4) False

1) Why is mtDNA so useful in forensic investigations?

mtDNA, found in the mitochondria, is very useful in Forensic Investigations because it resides in the follicular tag. If a piece of hair was forcibly removed, the follicular tag may be present which would most likely be rich in the source of mitochondrial DNA. This can then be used to link or identify a victim or suspect. This type of evidence that is usually referred to as Maternal DNA, if present, can be extracted from the follicular tag and be considered individual evidence to identify an individual.

1) How does class evidence differ from individual evidence? Provide an example of each.

1) They are both aspects of physical evidence. However, class evidence would be an item that can be related to or associated with another group of items that could potentially share the same characteristics. Basically, it narrows it down to a group of people. An example would be blood type and certain apparel. Individual evidence is and item that can be narrowed or traced to a single individual. It could also involve the comparison of another sample or control. An example would be DNA and fingerprints.

2) Describe how mtDNA differs from nuclear DNA and why it is often used in Forensics.

2) Mitochondrial DNA differs from nuclear DNA because it is found in mitochondria of each cell of a body unlike nucelar DNA. It differs from it because it is inherited by the mother and can be a match in family members pertaining to the mother's side. It is often used in Forensic because it is used with degraded, limited, and very small quantities of damaged DNA samples or evidence. Although it does not identify because of the shared mtDNA, it can be an important indicator in cases of missing persons and mass disasters. It's sources are also burned remains, hair shafts, old skeletal remains, and fingernails.

2) Discuss at least 3 uses of chromatography in Forensics.

2) One use of chromatography in forensic science would be to use it to analyze the dye or ink composition of fibers. A second use of chromatography would be to analyze and compare illicit drugs found and trace impurities. A third use of chromatography would be to identify components like accelerants and those of a bomb composition.

1) Blow Flies are from the family Sarcophagidae and typically arrive around 1-2 days after death.

1) false 2)

1) Handedness of the attacker can be accurately determined by studying stab wounds on a victim. 2) Environmental temperatures do not have an effect on Algor Mortis.

1) false 2) False

1) william sybers

1) mass spectrometry

2) Why do forensic scientists use models or exemplars for the evaluation of handwriting and document evidence?

2) An exemplar is a sample of handwriting whose source is known. Forensic Scientists use models or exemplars for the evaluation of handwriting and document evidence because it allows them to compare the handwriting of what the suspect was dictated to write and that of the questioned document in custody to determine any matches. The purpose of an exemplar is to compare it to a known document with a questioned document to identify any matching characteristics. Forensic Scientists use them because it provides insight on who the real perpetrator is and to do this they will use the model to look for grammar, punctuation, spelling, slants, shapes, etc. The idea of Automaticity may also be important because it appears when a suspect writes numerous things repeatedly now reverting back to their old writing habits if they were disguising their writing on purpose.

2) What is the estimated height in centimeters of an individual with a femur length of 17.5 inches? 1 inch= 2.54cm Formula: (Femur length X 2.6) + 65

2) Correct Femur lenght 17.5 inches. 17.5 inches = 44.45 cm (44.45 x 2.6) + 65 = 180.57 cm The estimated height in centimeters of an individual with a femur length of 17.5 inches is 180.75 cm.

2) Describe how Comparison Microscopes are used to evaluate firearms evidence. Include the following: -What type of firearms evidence is usually compared using this microscope? -What is the purpose in evaluating and comparing this evidence? -What are some of the specific characteristics of this evidence that are compared?

2) Firearm evidence that is usually compared using a comparison microscope is fired bullets, fired casings, and potential striation and tool marks. This also includes certain serial numbers or characters on the bullet or casings that link it to a certain weapon found at the scene or in police custody. The purpose of evaluating and comparing this evidence is to link the evidence to particular weapon which could in fact link it to a certain location, scene, or suspect. This could also give other information such as the trajectory of the shot and the way in which it was manufactured. Some specififc characteristics that are compared are the striation marks (markings and scratches) on the rifling that are made when the bore is drilled into. No two firearms with rifling will have the same marks therefore, making it individual evidence.

4) A Forensic Anthropologist's main goal is to create a Biological Profile. What is included in a Biological Profile?

4) A Biological Profile includes the general description of the decedent's probable appearance before death, sex, age at death, ancestry, stature, assesment of any visible trauma (antemortem, perimortem, & postmortem), and the notation of any diseases detected.

2) What is the difference between a Medical Examiner and Coroner?

2) Medical Examiners are doctors with board certification in Pathology or Forensic Pathology. They typically train for 13-15 years after high school for this career. A Coroner is an elected official who may or may not have medical training. Coroners are required to have a high school diploma, be at least 25 and be a resident in their county for a minimum of generally about 2 years.

Explain how the Daubert Ruling evolved from the Frye Standard.

Initially, The Frye standard began with the case Frye v. United States in 1923 as a test to determine admissability of scientific evidence. The Frye Standard would provide that expert opinion based on scientific techniques that are admissable only where the technique is generally reliable in the scientific community. However, The Daubert Ruling in the case Daubert v. Merrell Dow Pharamceuticles 1993, would be an overall revision of the Frye Standard. The Daubert Ruling now requires much more rigrous applications of the scientific method such as hypothesis, testing, estimations or error rates, peer-revision, publication, and over all generall acceptance. The evolution happened because courts wanted to avoid the same issues that happened in the Daubert case with expert witnesses presenting unreliable and questionable evidence or findings.

1) Discuss at least 2 ways that human remains can be distinguished from non-human animal remains.

One way that human remains can be distinguished from non-human animal remains would be through Gross Skeletal Anatomy. This would be the charactersistics of the bones that can be observed by the unaided eye such as quanitity or orientation. A second way to distinguish human remains from non-human would be Bone Microstructure. It is when people observe the microscopic structure and characteristics of the bone. For example, a human bone's osteocytes would be scattered and evenly spaced.

1) How is a digital watermark used to analyze and interpret evidence from digital sources?

1) A digital watermark is a pattern of data inserted into a digital image, audio, or video file that identifies the owner of the copyright for the content as well as the rights to use the content. It is used to analyze and interpret evidence from digital sources because it is usually present in criminal cases that deal with digital piracy. The watermark is usually only detected by a special program that specifically extracts digital watermarks. This is used in evidence when investigators deal with a case in which content has been downloaded, copied, and shared despite the coppyright making it an illegal copy of content.

1) Chromatography separates mixtures. A pure substance is not a mixture.Why is chromatography not useful for a pure substance?

1) A pure substance is a substance that is not made up of complex and numerous chemical particles. It is solely made up of one and has a fixed constant structure. Chromatography is used as a technique to seperate the components of a chemical structure or mixture by moving it along a stationary material such as gelatin. Chromatography is not useful for a pure substance as it is not able to seperate it into numerous compartments or spots that can form bands (for example, ink) to be analyzed.

1) Which major crime lab would typically be involved in the arson investigation of an apartment building which resulted in millions of dollars in damages? 2) A federal crime lab that specializes in investigating mail for suspected mail offenses such as fraud or mailing of banned substances: 3) Which of the following governmental agencies maintain their own crime labs?

1) ATF 2) USPIS 3) DEA

1) When developing models to analyze and communicate information obtained from a crime scene, investigators will often create a crime scene sketch. What is the difference in a rough sketch and a scale sketch?

1) An overall crime scene sketch usually highlights the orientation and location of the evidence without the cluttered appearance of a photograph. A rough sketch would be the very first sketch at the scene. It would be in pencil, drawn potentially not to scale, and with distances marked. A scale sketch would be the very final copy. It would accurately scaled with units such as 1/4 " per feet. It would usually lable the North at the top and would be orientated from trees, walls, polls, curbs, and immovable objects,

1) Describe ALL of the following: 1 indicator of Antemortem trauma 1 indicator of Perimortem trauma 1 indicator of Postmortem trauma

1) Antemortem trauma occurs before death. One indicator of Antemortem trauma is a degenerate joint disease or possibly a healed fracture. Perimortem trauma is truma that occured at or during the event that caused the death. One indicator of Perimortem trauma is broken bones that show no signs of repair or healing or fractures with plastic response. Postmortem trauma occured after death and is refered to as damages rather than injuries. One indicator is evidence of animal tooth marks on the bones.

1) Explain why drugs are considered harmful to others in society besides the actual user.

1) Drug use impacts many in society outside of the actual user. Users may commit crimes in order to obtain drugs to feed their addiction. A person under the influence of drugs may make decisions (such as driving impaired) which endanger the lives of others not using.

1) Identify 3 reasons why stereoscopic microscopes are so versatile in the crime lab.

1) Exemplary answers include at least 3 reasonable answers such as: 3D views of the image Can evaluate large or dense objects Can be used as a screening tool to analyze evidence without damaging it before being sent for more intrusive analytical procedures. Can be used to view living organisms Can be used to aid in dissection

1) What causes Livor Mortis and how can it be used to determine if a body has been moved?

1) Exemplary answers include: Livor Mortis is a purple coloration of dependent parts, except in areas of contact pressure, appearing within 30 minutes to 2 hours after death, as a result of gravitational movement of blood within the vessels. Because Livor Mortis patterns form in the areas lying closest to the ground due to gravity, investigators can often determine if a body has been moved after death. If the patterns are facing upward or in a manner not consistent with the blood pooling at the lowest point of the body, the body has most likely been moved.

1) A Forensic Archaeologist only works with buried ancient remains. 2) Trace evidence is defined as small amounts of physical evidence that can be analyzed for clues from a crime scene. 3) Forensic Archaeologists can reconstruct crime scenes to help provide more details about the crime. 4) The proper procedure for collecting paint evidence on clothing is to scrape it off of the cloth into a clean paper bindle. Then, secure it with tape and send to the lab. 5) A log of the photos made at the crime scene should always be updated and a copy kept with the crime scene report documentation.

1) False 2) True 3) True 4) False 5) True

1) The scanning process and magnetic lenses used in a scanning electron microscope often results in fair to poor resolution and "fuzzy" images. 2) A stereoscopic microscope has two eyepieces; the left eyepiece views the right lens while the right eyepiece views the left lens. 3) If the wavelengths match up in both samples being compared in a microspectrophotometer, the scientist could conclude that the colors are a match. 4) Refraction is the bending of a light wave as it travels from one medium to the next.

1) False 2) false 3) true 4) true

1) What does he need to note in the report? 2) What did the investigator do incorrectly 3) How is class evidence useful in a case?

1) He must note the original reclining position of the victim near the hot oven, the direction and distance the victim was moved and why, and the distance and direction the bloody knife was moved as the victim was moved. 2) He did not complete the chain of custody documentation or keep the evidence within his control the entire time. He also handed off the evidence to another person without having that person complete the chain of custody documentation. 3) Multiple pieces of class evidence can be combined to calculate the probability of originating from a specific source or person as in the Wayne Williams case.

1) List, describe and give an example of each of the five manners of death.

1) Homicide- The intent to cause fear, harm or death is considered homicide if the act results in death. Examples: Crimes of passion, pre-meditated murders, vehicular homicide. Suicide-Fatal wounds that are self-inflicted. Example: Intentional overdose. Accident-When there is no evidence that the injury or poisoning sustained occurred with intent to cause harm or death, the death is ruled accidental. Examples: car accidents, accidental drug overdose, falls. Natural- Death occurs due to a natural disease process such as heart disease, stroke or cancer. Undetermined- Deaths where the cause and manner can't be determined are designated as undetermined. Example: A body too badly decomposed to determine manner or cause of death.

1) Who developed the first true stereoscopic microscope? 2) How might a forensic scientist evaluate bullets to verify if they are a match beyond just looking at them? 3) Why is oil used with an oil immersion lens? 4) The scanning electron microscope can magnify up to: 5) Who created the prototype of the modern scanning electron microscope in 1948? 6) How is a pseudoscope different from a stereoscope microscope? 7) Which of the following is directly related to the clarity of the magnified image?

1) Horatio Greenough 2) Use colored filters to overlay the left and right images, one over the other, to look for darkened areas. 3) The oil changes the index of refraction so that the image has better resolution at higher levels of magnification. 4) 300,000x 5) Sir Charles Oatley 6) The images from the left and right eyepieces are reversed in a pseudoscope which inverts the 3D image vertically. 7) Resolution

1) Explain the significance of impression evidence in an investigation.

1) Impression evidence is very significant in an investigation. It is related to tool marks as they are impressions or scratches made when contact occurs with the tool and another object. They are observed for striations on tools to compare them to marks caught at the crime scene which can therefore, link the tool to another scene or suspect. For example, some of these marks are abrasion marks, cutting marks, and indentation marks. They are very important because if the tool which caused the marks is placed back into the scene it can alter the mark. This is why impression evidence should be collected with plaster molds. Other impressions are tire, shoe, and fabric impressions. This can allude to a potential hit and run situation with the fabric impression on the vehicle.

2) If an average sized person was found to have 15 mg of alcohol in a 100 mL sample of blood, what is their BAC? Should this person operate a vehicle?

1) Their BAC would be 0.15. This person should definitely not be operating a vehicle. Their level of BAC alludes to them dealing with diffiuclty standing, walking, and nausea. They would be twenty times more likely to be involved in a fatal accident then a sober driver. (0.8 is limit)

1) How can insect life cycles be analyzed to estimate the time of death?

1) Insect life cycles can be analyszed to estimate the time of death because (depending on the weather) it is possible to estimate a range or calculate the postmortem interval by looking at each individual stage of the colonization of the body. Insects have finite life cycles that can be compareed to precedding databases of that specific insect to determine how long the body may have been exposed. All of this would be impacted by several factors such as temperature and weather at the time. Additionally, depending on the stage of the insects life cycle, it can be submitted to Entomotoxicology testing to determine anything about the body in the advanced stage of decomposition. Additionally, Forensic Entomologists can use timetables of metamorphosis progression in a species' life cycle to aproximate the time of death. This would include the use of insect succession. Lastly, they can use ADD or ADH to predict how long the insect was in the corpse and predict the stage the insect should be in given the external temperatures.

1) If DNA structure is that of a twisted ladder, what would make up the rungs of the ladder?

1) Nitrogenous bases, or base pairs, make up the rungs of the ladder.

1) How are synthetic fibers manufactured?

1) Pieces of a polymer are melted and forced through a mold known as a spinneret. The resulting material is long strands of synthetic fiber that can then be used to manufacture other goods.

1) Examine the image at points A, B, and C. Explain what each point indicates and which impact occurred first. Also explain how you know which impact occurred first.

1) Point B indicates a Concentric Fracture and a second impact. Point A indicates a Radial Fracture and a first impact. Point C indicates a new fracture that terminated at an exististing line of fracture because the stress on the glass transfered to the already existing crack rather than crossing over it. Impact A (Radial Fracture) occured first. It occured first because the crack stopped the crack line of impact B (Cocentric Fracture).

1) List the 3 fundamental principles of fingerprints.

1) The first fundamental principle of fingerprints is that a fingerprint is an individual characteristic. No two fingerprints have been found to have the same ridge characteristics. Also, this proved that identical twins can have different fingerpints despite having the same DNA. A second fundamental principle is that fingerprints remain unchanged during a person's lifetime. Even burns, abrasions, and cuts will not impact the pattern or dermal papillae. The original pattern wil always grow back and be maintained. The third and final fundamental principle is that fingerprints will have general patterns that will allow them to be systematically classified.

1) The woman says she fell and cut it on a knife she was carrying, but also has bruising on other parts of her face. What type of injury is the wound that needs stitches and why do you think the doctor called you to investigate? 2) Livor Mortis comes from Latin and refers to the: 3) A body tends to lose an average of _____ (Fahrenheit) of body heat per hour from the time of death until the ambient temperature of the environment is reached. 4) Rigor Mortis generally begins and progresses: 5) Under which of the following set of circumstances can the Glaister equation be used to approximate the time of death? 6) Bacteria multiply and build up gases that become trapped in the body in a process known as: 7) About 24-36 hours after death, patches of green skin discoloration begin to show up on the abdomen. What is the cause of these green discolorations? 8) When evaluating Livor Mortis in the deceased, an investigator always looks to see that the Livor Mortis patterns are consistent with the position of the body. What causes the blood to pool in the lowest areas of the body?

1) This is a laceration. The tissue bridges and bruising indicate that it is a laceration caused by a blunt force trauma to the area and the woman's story did not match her wounds. 2) Death Color 3) 1.5 degrees 4) Head to foot 5) A body was found inside in an air conditioned room during a summer heatwave. The rectal temperature was between the temperature of the outside air and the cooler, air conditioned room. 6) Putrefaction 7) Bacteria Proliferation 8) Gravity

1) The term "Autopsy" comes from the Greek word, Autopsia, and means___________. 2) This Flemish physician received permission from the Catholic Church to dissect hanged murderers. He would often dissect these bodies in anatomical theaters in front of crowds. 3) Which of the following is NOT an example of evidence collected from the surface of the body during autopsy? 4) Which ancient Roman gladiator doctor would dissect animals before large public crowds to demonstrate progressive paralysis and anatomy? 5) If a woman is stabbed during a mugging and dies 9 days later as a result of an infection from the stab wound, what would be the manner of death?

1) To see oneself 2) Andreas Vesalius (wrote "De Fabrica Corpora Humani") 3) Vitreous Humor Sample 4) Galen of Pergamum 5) Homicide

1) Why is toxicology testing on insects so important and different from standard toxicology testing? 2) Insects can be used to determine if toxins or drugs are present in the corpse; this specialty of Forensic Entomology is known as:

1) Toxicology testing on the insects found in a corpse is so important because it can be done even if the body is in an advanced state of decomposition. Standard toxicology testing typically requires body fluids which may not be available in a state of advanced decomposition. Also, toxins such as Cocaine and Methamphetamine can affect the growth rate of the insects. 2) Entomotoxicology

1) In order the become a Medical Examiner, an applicant must become Board Certified in Pathology and Forensic Pathology. 2) Most religions do not allow autopsy. 3) Vitreous Humor is tested for drugs because drugs remain longer in the Vitreous Humor than in the blood. 4) Body bags and evidence sheets are washed with a 37% bleach solution and reused for multiple cases until they begin to show signs of wear. 5) An autopsy usually takes about 25-30 minutes to complete. 6) The top 3 causes of death are the same worldwide regardless of which country you examine; 1) Heart Disease 2) Cancer 3) Stroke

1) True 2) False 3) True 4) False 5) False 6) false

1) The FBI has over 500 scientific experts and agents. 2) Polygraph involves computer mapping of fingerprint characteristics on a suspect or victim. 3) The Evidence Collection department of a crime lab is concerned with collecting and preserving physical evidence. 4) Voiceprint analysis involves examining telephone threats and tape recordings for voice patterns to link to a specific person. 5) An example of the purpose of Deductive reasoning is to pinpoint a single person from a larger group by fact or observation, whereas the purpose of inductive reasoning is to generalize a conclusion from one particular source to a population as a whole. 6)The famous murder mystery board game where the players try to figure out who committed the murder by excluding various suspects until only one suspect is left is an example of inductive reasoning. 7) Forensic Scientists must have extensive on the job training from an experienced colleague before working independently on evidence collection and analysis. 8) A specific plan for collecting evidence is not important so long as the Forensic Scientist collects all of the evidence in the crime scene area. 9) A Forensic Scientist often meets with experts and specialists in various areas of Forensics and law to discuss and interpret evidence. 10) As a general rule, Forensic Scientists work independently rather than as a part of a larger team.

1) True 2) False 3) True 4) True 5) True 6) False 7) True 8) False 9) tRue 10) False

2) What are some of the ways in which an investigator could distinguish between a natural and synthetic fiber?

2) One way in which they can distinguish between natural and synthetic fiber would be throught the microscopic structure. A natural fiber will usually be less uniform and rough around the edges. A synthetic fiber would be more uniform and smooth around the edges. Another way would be the objects they are made from. A natural fiber would be made from plant and animal sources. A synthetic fiber would be made of monomers and polymers. Other ways would be by conducting physical characteristics exams such as counting the number of filaments, calculating density of fiber, evaluating refraction, and checking for fluorensence. Another set of exams that they can use for the comparison of the fibers would be oxidation tests, PH tests, evaluating residues, and chemical decomposition tests.

2) What is the Precipitin test used for?

2) The Precipitin test is mainly used as a measure of distinguishing a blood stain from human or other animal origin. This test can be done with the production of various serums for all species of animals in addition to the human testing serum which is the one most commonly used. This test is also used as an initial measure to determine the blood's origin and allow it to proceed to DNA analysis as well as having it tested for trace amounts of drugs and alcohol.

2) List and describe the 4 steps of the fingerprint analysis process.

2) The four steps of the fingerprint analysis process are the acronym ACE-V. They are analysis, comparison, evaluation, and verification. Analysis consists of analyzing print comparison qualities. This involves incomplete prints that are dismissed and suitable prints which are documented with matching minutiae and other things such as scars and tattoos. Comparison consists of comparing the prints of the person of interest to a known print for matching sets. An examiner will be looking for a match in 8-16 minutiae points. The matchings will be searched for in the national database, IAFIS. Evaluation consists of an examiner deciding if the prints match, do not match, or are inconclusive (meaning poor quality). Verification, the last step, involves the prints being evaluated by another examiner. If they both agree then they finish the analysis process. If the do not agree the process will be repeated or the the print will me deamed not usable or inconclusive.

2) When carrying out an investigation into soil analysis, why must the soil be examined when dry and when wet?

2) When carrying out an investigation into soil analysis, soil must be examine when dry and when moist because it usually appears darker when wet.

3) What is a DNA fingerprint and why is it considered individual evidence?

3) A DNA Profile is sometimes also called a DNA fingerprint. It is considered individual evidence because no two people have the same assortment of DNA sequence fragment lengths (except identical twins). Therefore, it can be compared to and commonly referred to as a fingerprint. Also, it is considered individual evidence because it can discern between people to either exclude or include from a given source or sample.

3) Why do families sometimes not give consent for autopsy?

3) Families sometimes do not give consent for an autopsy due to ethical and religious objections. Some say that an autopsy can lead to the disfiguration of the body, that the deceased has suffered anough, or that it may potentially interfere with funeral arrangements.

3) When and why does handwriting become unique to an individual?

3) Mid to late adolescence as they no longer rely on copying forms of letters and instead rely on subconcious effort in writing letterforms.

3) Describe at least 3 indicators that help determine the sex of the decedent.

3) One main indicator that helps determine the sex of a decedent would be the pelvis. The structure of a female would be accomodated for child birth. A second indicator that helps determine the sex of a decedent would be the skull. A male would have a larger skull and an over all larger mastoid process while a female would be the opposite. A third indicator that can help determine the sex of a decedent would be the angle of the Sciatic Notch. A female would have a 90 degree or larger angle while a male would have a 90 degree or smaller angle.

3) Discuss at least 3 uses of Mass Spectrometry in Forensics.

3) One use of Mass Spectromtery in Forensics would be to identify unknown substances such as powders and drugs. A second use would be to drug test athletes for any performance-enhancing or illegal substances. A third use would be to analyze accelerants that took part in arson cases.

3) Name and describe 2 types of tool marks.

3) Some of the most common types of tool marks include abrasion marks, cutting marks, and indentation marks. Abrasion marks are made when one surface slides across another and essentially scratching the surface. Cutting marks are produced along the edge as a surface is cut. Indentation marks are made when a tool is pressed against a softer surface resulting in an impression of the harder tool in the softer material.

3) Choose ONE of the following types of glass and describe the unique physical properties of it, the applications for its use and how it can be used as evidence in a forensic investigation:

3)Tempered Physical properties of tempered glass include resistance. It is impact resitant and is heated to a uniform temperature of 650c and cooled to induce compressive stress. Tempered glass can be used for safety measure applications. It can be used as vehicle windows, doors, architectural glass, etc. It can be used as evidence in an investigation as frgaments that can allude to a potential hit and run, for example. It can be examined for its various physical properties and can even be peiced together like a puzzle to potentially examine its origin (only if they do fit as glass never breaks in the same pattern).

4) What are the differences between a shotgun and a rifle? *Be sure to include details about the barrel and type of projectiles used

4) A shot gun is a firearm with a smooth bore or smooth barrel without the rifling. A rifle is a shoulder firearm with a rifled barrel which can only shoot one bullet at a time. Rifling is when spiral grooves are cut into the inside of the barrel surface causing a bullet to spin and stabalizing it. A shot gun does not have rifling whereas a rifle does. A shotgun shoots small pellets known as shots and slugs. In comparison a rifle shoots a single bullet through a rifled barrel which increases its range and accuracy.

4) Why should an investigator never allow unauthorized persons at the crime scene to assist in the collection of computers or devices?

4) Investigators should never accept help from any unauthorized person when securing electronic equipment. It could be someone connected to the crime trying to delete or alter evidence!

4) Explain how soil is formed in 3-5 sentences.

4) Soil is formed through the weathering of rocks. This includes water and wind that breaks down rock in the environement to form soil. When water freezes it expands and when concerning cracks in rocks, it can break it off into small peices which could then further wear out into soil. Wind blowing water onto a cliff or a river running up against rocks can break pieces off little by little as it forms dirt. Although, soil formation usually takes thousands of years.

5) What can soil evidence tell investigators?

5) Soil can inform investigators on the geograpgical features of a crime scene as well as how or where the body was moved from. It can pinpoint a certain area or location in which the body was moved from. It can also tell and generate various leads for the investigators. It can also help place a suspect at a crime scene.

6) Explain why being able to match glass fragments and put them back together like a puzzle would be confirmation that the glass pieces were from the same source. Would this be individual or class evidence?

6) Individual evidence; glass is an amorphous soild which means that its atoms are randomly distributed. This random distribution causes each article of glass to shatter in a unique pattern. Being able to put them back together as a puzzle indicates that the glass fragments must have come from the same glass source.

7) How can glass evidence be useful in a forensic investigation?

7) Glass evidence can be useful in a forensic investigation because it can identify matches on the victim, suspect, and scene. Although it is considered class evidence, it can contain pieces of individual evidence such as blood, hair, and fingerprints that could lead to a specific source. It is also useful in forensic investigations because it can be linked back to a common source. Glass can be transferred to another person, animal, or object near the scene and it can give a very large lead on who the suspect may be if there was a match.

1) How does a polarizing lens on a polarizing microscope work?

A polarizing microscope is actually pretty similar to a light microscope but it also has a polarizer. The polarizer in the condenser (which can be rotated) decomposes a ray of light into two rays of different velocities known as befringence and a double refraction. Befringence would be measured by the measuring of the differences between two indices of refraction. A polarizing microscope highlights structural differences that can not be seen in natural lighted conditions. These differences can then be used to identify the materials tested. It is used to study crystalline solids, illicit drugs, and fibers. It inhances the the contrast between the material and the background which would usually reveal information regarding the structure and composition. -Exemplary answers should include that a polarizing lens only allows light moving in a particular direction through and blocks all other directions of the light ray.

1) Construct an explanation for how the Precipitin test is used to distinguish animal blood from human blood.

Precipitin is an antibody that reacts with its corresponding antigen to form a precipitate if the blood is from a human. The Precipitin Test's basic principle is that a serum with anti-human antibodies is poured into a blood sample. If the blood sample were to clot, then the blood must be from a human. This serum is an Anti-Serum which is retreaved by injecting human blood into an animal so that it can develop antibodies against the human blood. The antibodies would then be extracted and used in a testing serum. After, if the blood is identified as human, then they can proceed with DNA evidence that may link the blood to a specififc individual.

What is the difference between deductive and inductive reasoning? Why is deductive reasoning considered the basic framework of a typical Forensic Investigation?

The difference between deductive and inductive reasoning would be that deductive is a type of reasoning in which an individual gradually reduces the options from the most general principles to the most specific. However, inductive would be the opposite as it initially focuses on specific instances and moves towrds generalizations and theories. Deductive Reasoning is considered the framework of a typical Forensic Investigation because Investigators rely upon details and clues to eliminate suspects. It is a methodical way in which Investigators process all of the general information of a crime to narrow down specific suspects or ideas.