Forensics CTE Test Chapter 2: The Crime Scene

Describe a druggist fold (bindle) and explain why it is a superior way to package small amounts of trace evidence.

A druggist fold consists of folding one end of a piece of paper over one-third, then folding the other end (one third) over that, and repeating the process from the other two sides. After the paper is folded in this manner, the outside two edges are tucked into each other. A druggist fold produces a closed container that keeps the specimen from falling out.

What is a rough sketch and what information must it accurately reflect?

A rough sketch is a draft representation of all essential information and measurements at a crime scene. A rough sketch must accurately depict the dimensions of the crime scene, as well as all recovered items of physical evidence and their exact locations.

What is a standard/reference sample and why is it important to the criminalist?

A standard/reference sample is physical evidence whose origin is known, such as blood or hair from a suspect, which can be compared to crime-scene evidence. Standard/reference samples are important because they allow the criminalist to connect evidence found at the scene of a crime to the suspect and/or victim.

What is a substrate control and why is it important?

A substrate control consists of uncontaminated surface material close to an area where physical evidence has been deposited. A substrate control ensures that the surface on which a sample has been deposited does not interfere with the interpretation of laboratory tests.

Why should bloodstained evidence not be stored in airtight containers? What is the best way to store such evidence?

Bloodstained materials should not be stored in airtight containers because the accumulation of moisture in such containers may encourage the growth of mold, which can destroy the evidential value of blood. In these instances, wrapping paper, manila envelopes, and paper bags are recommended packaging materials.

What information must be included in any notes taken at the crime scene?

Crime scene notes must include a detailed written description of the scene with the location of items of physical evidence recovered. They must also identify the time at which an item of physical evidence was discovered, by whom, how and by whom it was packaged and marked, and the disposition of the item after it was collected.

A warrantless search may be justified in the following situations: (1) the existence of emergency circumstances; (2) the need to prevent the immediate loss or destruction of evidence; (3) a search of a person and property within the immediate control of the person, provided it is made incident to a lawful arrest; and (4) a search made by consent of the parties involved.

List four situations in which a warrantless search may be justified.

Why should ordinary mailing envelopes not be used for packaging physical evidence?

Ordinary mailing envelopes should not be used as evidence containers because powders and fine particles will leak out of their corners.

Why is it important to package items of physical evidence in separate containers?

Packaging evidence separately prevents damage through contact and cross contamination.

How does the textbook define physical evidence?

Physical evidence is any object that can establish that a crime has been committed (not testimony)

How does the textbook define physical evidence?

Physical evidence is any object that can establish that a crime has been committed, or can link a crime and its victim or a crime and its perpetrator.

Why is it important to include a brief description of the case history on an evidence submission form?

Providing a case history allows the examiner to analyze specimens in a logical sequence and make the proper comparisons, and it also facilitates the search for trace quantities of evidence.

Besides the crime scene itself what locations must investigators search?

The areas searched must include all probable points of entry and exit used by the criminal(s)

Define chain of custody and explain why maintaining a proper chain of custody is important. What are the possible consequences of failing to maintain a proper chain of custody?

The chain of custody is a list of all people who came into possession of an item of evidence. Maintaining a proper chain of custody is the best guarantee that the evidence will withstand inquires of what happened to it from the time of its finding to its presentation in court. Failure to substantiate the evidences chain of custody may lead to serious questions regarding the authenticity and integrity of the evidence and examinations of it.

What items from deceased victims must be collected and sent to a forensic laboratory?

The following items must be sent to the forensic laboratory: the victim's clothing, fingernail scrapings, head and pubic hairs, blood, bullets recovered from the body, hand swabs (from shooting victims), and vaginal/anal/oral swabs (in sex related crimes).

What is the best way to maintain the integrity of evidence that is collected and submitted to the crime laboratory?

The integrity of evidence is best maintained when the item is kept in its original condition as found at the crime site.

What is the most important prerequisite for photographing a crime scene? Why is this so critical?

The most important prerequisite for photographing a crime scene is for the scene to be in an unaltered condition. If objects at the scene have been removed, added, or changed positions, the photographs may not be admissible as evidence at a trial, and their intended value will be lost.

List three methods of crime scene recording.

The three methods of crime scene recording are photography, sketches, and notes.

What is the main objective in collecting and packaging physical evidence?

To prevent any change in the evidence between the time it is removed from the crime scene and the time it is received by the crime laboratory.

The spread of AIDS and hepatitis B have sensitized the law enforcement community to the potential health hazards that can exist at crime scenes. Three basic types of protective clothing recommended for the investigators are latex gloves, shoe covers, and liquid-repellent coveralls.

What two diseases have sensitized the law enforcement community to the potential health hazards that can exist at crime scenes? Name three basic types of protective clothing that investigators used to guard against contamination by infectious materials at a crime scene.