Forensic Science Exam Review

Comprehensive practice flashcards in Question and Answer format covering Chapters 1 through 14 of the forensic science lecture notes.

How is forensic science defined in the course text?

The application of science to criminal and civil laws, especially matters enforced by police agencies in the justice system.

What is the CSI effect?

The phenomenon in which jurors develop unrealistic expectations of forensic evidence and investigative techniques, influenced by crime-scene television shows.

What system of personal identification did Alphonse Bertillon develop?

Anthropometry, a system of personal identification based on bodily measurements that was considered highly accurate for identification for about two decades.

What was Edmond Locard's contribution to forensic science?

He was a major contributor who incorporated Hans Gross's principles into a workable crime laboratory.

What guideline for the admissibility of scientific evidence was established by Frye v. United States?

The questioned method must be generally accepted by the relevant scientific community.

What did the U.S. Supreme Court rule regarding scientific admissibility in Daubert v. Merrell Dow Pharmaceuticals Inc. (1993)?

The court held that the Frye standard is not an absolute prerequisite for admissibility.

According to the Federal Rules of Evidence (Rule 702), who qualifies as an expert witness?

An individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person.

Who is responsible for securing the crime scene during the initial response?

The first responding police officer.

What are the first priority actions to get done at a crime scene?

Obtain medical assistance for injured victims, detain potential suspects or witnesses and obtain statements, secure the crime scene, and call for additional personnel.

What takes place during the initial survey (walk-through) of a crime scene?

Investigators follow an indirect path to the center, locate and document obvious evidence, and observe and record scene conditions.

How do line/strip and grid search patterns operate?

In a line/strip search, one or two investigators search in straight lines across the scene; in a grid search, two or more investigators form a grid.

What are the 'big 3' methods of crime-scene recording?

Photography, sketches, and notes.

What is the standard focal length of a normal camera lens, and what does it show?

$50\text{--}55\,\text{mm}$, which is used for most crime-scene photos and shows about half a wall.

How does aperture setting relate to f-number (f-stop)?

The lower the f-number, the wider the aperture and the more light is let in.

What is the most important prerequisite for crime-scene photography?

That the scene is in an unaltered condition.

What specific information must be recorded at the top of a crime-scene photography log?

Case number, type of scene, date, location of scene, description of camera and lenses used, and the photographer's name and title.

What are the three compositional views taken when photographing a crime scene?

Overview, medium-range, and close-up photographs.

What is the definition and purpose of a rough sketch?

A sketch made at the scene that accurately shows the dimensions of the scene and the location of all pertinent objects and features.

How is physical evidence defined?

Any and all objects that can establish whether a crime has or has not been committed, or that can provide a link between a crime and its victim or a crime and its perpetrator.

In what containers should biological or bloodstained evidence be packaged?

Breathable containers such as paper bags, manila envelopes, or cardboard boxes.

What is chain of custody, and why is it crucial?

A list of all persons who came into possession of an item of evidence; it must be established whenever evidence is presented in court to prove continuity of possession and maintain integrity.

What is a standard/reference sample?

Physical evidence whose origin is known (such as blood or hair from a suspect) that can be compared with crime-scene evidence.

What is the forensic definition of identification?

Determining the physical or chemical identity of a substance with as near absolute certainty as existing analytical techniques permit.

What is the difference between individual characteristics and class characteristics?

Individual characteristics associate evidence with a common source with an extremely high degree of probability; class characteristics associate evidence only with a group, not a single source.

What is forensic palynology, and what tool is principally used to analyze it?

The collection and examination of pollen and spores connected with crime scenes, illegal activities, or terrorism; the microscope is the principal tool.

What is the primary difference between a coroner and a medical examiner?

Coroners are elected officials who may or may not have a medical degree, while medical examiners are almost always appointed officials and usually physicians who are board-certified forensic pathologists.

What are the five manners of death?

Homicide, suicide, accidental, natural, and undetermined.

What is algor mortis, and at what rate does it occur?

The postmortem loss of body heat, generally occurring at a rate of $1\text{ to }1.5^\circ\text{F}$ per hour until the body reaches environmental temperature.

What four skeletal characteristics can be revealed in a biological profile by forensic anthropology?

Sex, approximate age, race, and skeletal injury (with height estimated from the long bones).

How does forensic entomology help determine the postmortem interval (PMI)?

By identifying the oldest stage of fly found on a body and analyzing the sequence of arrival of different insect species.

What is crime-scene reconstruction?

The method used to develop a likely sequence of events at a crime scene by observing and evaluating physical evidence and statements made by individuals involved with the incident.

What is direct physical evidence in crime-scene reconstruction?

Evidence that provides a definite conclusion or direction through deductive reasoning, stating a fact that everyone can understand.

What skin layer determines the pattern of ridge characteristics on the skin's surface?

The dermal papillae, which are the layer of cells between the outer epidermis and the inner dermis.

What are the three main classes of fingerprints?

Loops, arches, and whorls (L.A.W.).

What are the four steps of the ACE-V process for fingerprint examination?

Analysis, Comparison, Evaluation (Identify), and Verification.

How do visible, plastic, and latent fingerprints differ?

Visible prints are made when fingers touch a surface after contacting a colored material (blood, paint, ink); plastic prints are impressions left in soft material (putty, wax, soap); latent prints are invisible impressions formed by sweat and oils.

What is RUVIS and when is it utilized?

Reflected Ultraviolet Imaging System; a nondestructive method used to detect latent fingerprints on hard, nonabsorbent surfaces before applying powders or superglue.

What are the three phases of human hair growth?

Anagen (early/growth phase), catagen (middle phase), and telogen (final phase).

What is a follicular tag, and why is it forensically important?

Translucent tissue surrounding the hair shaft near the root when pulled from the head; it is forensically significant because it can be a rich source of nuclear DNA.

What type of DNA can be extracted from the hair shaft?

Mitochondrial DNA.

What instrument is indispensable for comparing morphological characteristics of hair and fibers?

A comparison microscope.

How is tempered glass manufactured to make it stronger than normal glass?

Its surfaces undergo rapid heating and cooling.

What is laminated glass?

Glass used in car windshields that has a plastic layer sandwiched between two pieces of ordinary window glass.

What is a Becke line?

A bright halo near the border of a glass particle immersed in a liquid having a different refractive index.

Where and in what order do radial and concentric fractures form on glass?

Radial cracks form first on the side opposite the destructive force; concentric cracks form outward, starting on the same side as the force.

What is the protocol for collecting standard/reference soil samples?

Collect reference soils at various intervals within a $100\,\text{foot}$ radius of the crime scene and at the crime site for comparison.