Question: What is the difference between a crystalline

> Police investigating the scene of a sexual assault recover a large blanket that they believe may contain useful physical evidence. They take it to the laboratory of forensic serologist Scott Alden, asking him to test it for the presence of semen. Noticin

> What important elements are missing from the following crime-scene sketch?

> Criminalist Jared Heath responds to the scene of an assault, on an unpaved lane in a rural neighborhood. Rain had fallen steadily the night before, making the area quite muddy. A suspect with very muddy shoes was apprehended nearby but claims to have pic

> Only a handful of crime laboratories worldwide have access to a nuclear reactor to carry out neutron activation analysis. What are some possible reasons why this is so?

> A forensic analyst at the local crime lab receives pieces of a disfigured bullet from a crime scene. She then obtains an exemplar bullet fired by the firearms analyst from the suspect’s firearm. What is the next step in analysis?

> You are investigating a hit-and-run accident and have identified a suspect vehicle. Describe how you would collect paint to determine whether the suspect vehicle was involved in the accident. Be sure to indicate the tools you would use and the steps you

> You are investigating an arson scene and you find a corpse in the rubble, but you suspect that the victim did not die as a result of the fire. Instead, you suspect that the victim was murdered earlier, and that the blaze was started to cover up the murde

> You are a forensic scientist who has been asked to test two blood samples. You know that one sample is suspected of containing barbiturates and the other contains no drugs; however, you cannot tell the two samples apart. Describe how you would use the co

> Following is a description of four individuals who have been drinking. In which (if any) of the following countries would each be considered legally drunk: the United States, Australia, Sweden? a. Bill, who weighs 150 pounds and has consumed three 8-ounc

> Following is a description of four individuals who have been drinking. Rank them from highest to lowest blood-alcohol concentration: a. John, who weighs 200 pounds and has consumed eight 8-ounce drinks on a full stomach b. Frank, who weighs 170 pounds an

> Answer the following questions about driving risk associated with drinking and blood-alcohol concentration: a. Randy is just barely legally intoxicated. How much more likely is he to have an accident than someone who is sober? b. Marissa, who has been dr

> When investigating a potential warehouse for storing illegal drugs, the police collected a variety of drugs. The drugs were tested with presumptive color tests for determining their possible identity. The test tubes shown in the following figure display

> Evidence Processing at the Crime Laboratory You are the evidence technician at the front desk of the state crime lab. You receive the following items of evidence to check in on a very busy day. You must indicate which unit each piece of evidence should b

> The following figure shows a chromatogram of a known mixture of barbiturates. Based on this figure, answer the following questions: a. What barbiturate detected by the chromatogram had the longest retention time? b. Which barbiturate had the shortest ret

> A police officer stops a motorist who is driving erratically and notices a bag of white powder on the front seat of the car that he suspects contains heroin. The officer brings the bag to you, a forensic scientist in the local crime lab. Name one screeni

> Following are descriptions of four hypothetical drugs. According to the Controlled Substances Act, under which drug schedule would each substance be classified? a. This drug has a high potential for psychological dependence, it currently has accepted med

> Following are descriptions of behavior that are characteristic among users of certain classes of drugs. For each description, indicate the class of drug (narcotics, stimulants, and so on) for which the behavior is most characteristic. For each descriptio

> An individual who has been using a drug for an extended period of time suddenly finds himself unable to secure more of the drug. He acts nervous and irritable and is hyperactive. He seems almost desperate to find more of the drug, but experiences no sick

> What is Locard’s exchange principle?

> How did Calvin Goddard advance the science of firearms examination?

> What was Francis Galton’s principal contribution to forensic science?

> A young child is kidnapped from her school playground. Shown below is a reference sample of the kidnapped child’s hair. The only cars that left the parking lot before the child was discovered to be missing were those of four cafeteria w

> Why is Mathieu Orfila considered “the father of forensic toxicology”?

> How does the textbook define forensic science?

> What aspect of the hair cortex is most important for the criminalist and why?

> Name two analytical devices used by forensic scientists to determine the class of a fiber.

> How can micro-spectrophotometry and chromatography be used to analyze fiber evidence?

> What is the first and most important step in the examination of a fiber? What physical characteristics of fibers might help an examiner identify it?

> How has mass production limited the value of fiber evidence?

> How is the hair cuticle used to identify different animal species?

> What physical change occurs when a substance undergoes the following changes of state: (a) From liquid to solid, and (b) From liquid to gas?

> Name the three forms, or states, of matter and explain how the shape and volume of matter are expressed in each state.

> The most common scale patterns found on hairs are generally classified as coronal, spinous, and imbricate. Examine the scale casts of animal hairs shown here and indicate the scale pattern of each.

> Define element and compound and name the smallest unit of each.

> Define weight and mass and explain the difference between the two concepts.

> List the two most commonly used temperature scales and their respective reference points.

> What reference points are most often chosen when constructing a temperature scale?

> List the basic units of length, mass, and volume in the metric system.

> How can an investigator determine the order in which several successive penetrations of a glass occurred?

> What is the 3R rule and how is it applied to the analysis of glass fractures?

> What is the Becke line and how is it used to determine the refractive index of a glass sample?

> Describe the process of flotation and explain what it is used for.

> Why is the metric system of measurement easier to use than the “English system”? Which system is used in the United States?

> For each of the following human hair samples, indicate the medulla pattern present.

> List two factors that make it difficult for criminalists to compare glass samples.

> What two models do scientists use to explain the nature of light? Under what conditions does each model best describe the behavior of light?

> What is color? What determines the color of an opaque object?

> Define intensive property and name two intensive properties of matter.

> Explain how a prism disperses white light into its constituent colors.

> Define the terms refraction and refractive index.

> What is density? How does heat affect the density of gases and liquids?

> What is a phase and how can two different phases be distinguished from one another?

> Define sublimation. What happens to the attractive forces between molecules of a substance that undergo sublimation?

> Criminalist Pete Evett is collecting fiber evidence from a murder scene. He notices fibers on the victim’s shirt and trousers, so he places both of these items of clothing in a plastic bag. He also sees fibers on a sheet near the victim, so he balls up t

> Define the terms physical property and chemical property.

> What is the Greiss test and what two pieces of information can it provide to an investigator?

> List three characteristics of a bullet hole that indicate that the shot was fired at extremely close range.

> What evidence does an investigator study to make a distance determination? How can test-firing a suspect weapon help the investigator make a distance determination?

> What is distance determination? Describe two situations in which distance determination can establish the facts of a shooting incident.

> Why does a firearms examiner test-fire bullets from a suspect barrel?

> Besides the barrel, what parts of a firearm may leave distinctive markings on a shell cartridge?

> List two reasons why striations on bullets fired from the same gun may vary slightly.

> What kinds of impression evidence might a forensic odontologist be asked to analyze? How might this help identify a suspect?

> Describe how a firearms examiner compares two bullets. What characteristic does an examiner most often use to identify bullets and why?

> Following are descriptions of several hairs; based on these descriptions, indicate the likely race of the person from whom the hair originated: a. Evenly distributed, fine pigmentation b. Continuous medullation c. Dense, uneven pigmentation d. Wavy with

> A Timeline of Forensic Science The following images depict different types of evidence or techniques for analyzing evidence. Place the images in order pertaining to the time in history (least recent to most recent) at which each type of evidence or techn

> What is the first thing the investigator does before handling or moving any impression at a crime scene? Why is this considered merely a backup or precautionary procedure?

> What techniques does an investigator use to analyze tool marks that cannot be removed from a crime scene? What is the disadvantage of this technique?

> Name two types of marks that impart individuality to a tool and explain how the marks are made.

> What is the investigator’s primary concern when collecting and handling bullets and cartridge cases? Why must the investigator exercise extreme caution when removing a bullet lodged in a wall or other object?

> What characteristics of a suspect firearm should an investigator record before unloading it? Why should the investigator number the chambers and cartridges when unloading a suspect weapon?

> Why would an investigator not pick up a weapon by its barrel with a pencil or stick in order to protect latent fingerprints? How should suspect firearms be handled in such a situation?

> Describe how a criminalist restores an obliterated serial number on a weapon.

> Why does analysis of primer residue from a suspect’s hands produce a low rate of positive results? Why is such analysis typically ineffective in locating primer residue from a . 22-caliber gun?

> What evidence do investigators look for when trying to determine whether a suspect has fired a handgun? Where is such evidence typically found and why?

> How is shot pattern used to make a distance determination for shotgun blasts? What factors other than distance to target can affect the distance determination?

> A criminalist studying a dyed sample hair notices that the dyed color ends about 1.5 centimeters from the tip of the hair. Approximately how many weeks before the examination was the hair dyed? Explain your answer.

> List three class characteristics of a gun barrel.

> How did the comparison microscope make possible modern firearms examination?

> Briefly describe how a comparison microscope works and what it is used for.

> Why might an examiner choose a microscope with a lesser magnification to study a specimen?

> What does numerical aperture (N.A.) measure? What is the difference between a lens with N.A. 1.0 and one with N.A. 0.5?

> What is the difference between a real image and a virtual image?

> How does one calculate the magnification power of a compound microscope?

> What is vertical illumination and under what conditions would a forensic scientist use it to examine a sample? Why is it superior to transmitted illumination under such conditions?

> Why does a compound microscope produce greater magnification than a magnifying glass? How does the eyepiece lens contribute to magnification?

> How can a scanning electron microscope be used to determine whether a suspect has recently fired a gun?

> Indicate the phase of growth of each of the following hairs: a. The root is club shaped b. The hair has a follicular tag c. The root bulb is flame shaped d. The root is elongated

> How can a scanning electron microscope be used to identify the elements present in a specimen?

> What is the basic difference between a scanning electron microscope and the other microscopes used in the crime laboratory?

> Explain how the infrared micro-spectrophotometer determines the identity of a specimen. What type of physical evidence is the micro-spectrophotometer typically used to analyze?

> What is the main advantage of the micro-spectrophotometer?

> What happens to a light beam that passes through a polarizing crystal? What happens when plane-polarized light passes through a second polarizing crystal set perpendicular to the first crystal?

> What is the most widely used microscope in the crime laboratory? What features make it particularly suited for examination of physical evidence?

> List two unique characteristics of the stereoscopic microscope.

> How does a magnifying glass enlarge objects viewed through it?

> Which module is responsible for saving all of the raw data produced by feature extraction and putting it into a simple and easy to read format for the system?

> What biometric system process or module performs most of the “heavy lifting” for the system?

> The accompanying figure depicts stress marks on the edge of a glass fracture caused by the application of force. If this is a radial fracture, from which side of the glass (left or right) was the force applied? From which side was force applied if it is

> What is the first process that each biometric system must perform? What does it consist of?