CSI Exam 2 Study Guide

What are the three types of fingerprints?

Patent, plastic, and latent prints.

What distinguishes patent fingerprints?

They are visible to the naked eye due to contamination with foreign materials.

What are plastic fingerprints?

Impressions left in soft materials like clay or playdough.

What are latent fingerprints?

Fingerprints resulting from grease, sweat, and dirt, requiring development to be visible.

What is the composition of fingerprints?

Ridges formed by fine patterns, with sweat pores left behind as moisture and solids.

What percentage of fingerprints are arches?

5%.

What percentage of fingerprints are loops?

70%.

What percentage of fingerprints are whorls?

25%.

What defines ulnar loops?

Loops that enter and exit towards the pinky finger.

What are radial loops?

Loops that enter and exit toward the thumb.

How do plain whorls differ from other whorls?

They have a complete circle with 2 deltas and type lines that touch one side of the inner pattern.

What defines a central pocket loop whorl?

It has a complete circle with two deltas and does not cut through any patterns.

What characterizes a double loop whorl?

It has two distinct loop formations and two deltas.

What is an accidental whorl?

A pattern combining two or more designs with two or more deltas.

What characterizes a plain arch?

Ridges that enter from one side of the print and exit on the opposite side.

What is a tented arch?

Similar to a plain arch, but with a sharp up-thrust spike of ridges.

How do you count ridges in fingerprint analysis?

Count the number of ridges between the delta and core along a connecting line.

What is the first technique for locating latent prints?

Visual examination.

What surfaces are suitable for powder dusting techniques?

Hard, non-absorbent surfaces.

What is the primary use of black fingerprint powder?

Used on light surfaces for developing prints.

What type of powder is effective for rough, grained surfaces?

Magnetic powder.

What does Ninhydrin react with to reveal fingerprints?

Amino acids in sweat.

What color print does Ninhydrin produce?

Purple print known as Ruhemann's purple.

What is the purpose of the exclusionary rule?

To disallow the use of illegally obtained evidence in criminal trials.

What is primary evidence?

Evidence obtained directly from illegal conduct.

What is an example of an exception to the warrant requirement?

Consent given voluntarily by a citizen.

In what case did the exclusionary rule extend to state courts?

Mapp v. Ohio.

What is the purpose of the IAFIS?

An automated database for fingerprint comparisons maintained by the FBI.

What does the Brady Rule mandate regarding evidence?

Prosecutors must disclose exculpatory evidence to the defense.

What is meant by hearsay evidence?

Testimony or evidence not based on a witness's direct knowledge.

What is Locard's principle?

Every contact leaves a trace.

What is the best practice for securing crime scene integrity?

Conduct objective and impartial investigations.

What is the first step in processing a crime scene?

Secure the scene and establish evidence integrity.

What is the significance of the 4th Amendment?

Protection from unreasonable search and seizure.

What was the ruling in Weeks v. United States?

Warrantless searches violated the 4th Amendment.

What types of specimens are commonly collected for toxicology?

Blood, urine, and gastric content.

What should biological evidence NOT be packaged in?

Plastic packaging.

What types of evidence can DNA evidence provide a link to?

Crime scene, victim, and perpetrator.

What methods can be used for collecting trace evidence?

Picking, taping, vacuuming.

What is important to remember when collecting fiber controls?

Collect each color and kind from control samples.

What is the procedure for packaging wet evidence?

Items that may mold should be packaged in paper.

What should be included in the proper sealing of evidence?

Tamper-resistant tape and initials with the date.

What is the standard for obtaining request exemplars?

They must be prepared on demand, possibly requiring a court order.

What characterizes firearms as evidence?

They include handguns and long guns and have specific packaging requirements.

How long after a firearm discharge should GSR evidence be collected?

Within 4 hours of deposition.

What are some precautions when handling clandestine labs?

Avoid breathing vapors and contact with toxic substances.

What documentation should be made for digital evidence?

Label connections, record locations, and status of components.

What must be considered in the storage of evidence facilities?

Controlled access and climate control to prevent degradation.

What is the forensic significance of the 14th Amendment?

It mandates due process and equal protection under the law.

What is Amido Black used for?

Enhancing prints on non-porous surfaces, sensitive to blood proteins.

Why should DNA evidence be air-dried before packaging?

To prevent degradation and contamination.

What should be done with questioned evidence to avoid contamination?

Store in separate containers and change gloves between handling.

How should witness statements be handled in court?

Testimonial evidence can’t be used unless the witness is available for cross-examination.

What are the different types of evidence favorable to the accused?

Exculpatory, mitigating, and impeachment evidence.

What best practice should be followed when lifting latent prints?

Lift prints after photographing them.

What do you need to collect GSR residues effectively?

Outermost garment from the victim and suspect weapon.

What is super glue fuming used for?

To adhere vapors to fingerprint residues on non-porous surfaces.

What is the purpose of collecting controls in trace evidence analysis?

To serve as a comparison for analysis.

What constitutes digital evidence?

Any data derived from digital devices or networks.

What are the steps in processing crime scene evidence?

Secure, assess, document, process, and debrief/release.

What must be maintained to protect evidence chain-of-custody?

Document time, date, and personnel involved in evidence handling.

How can improper evidence handling impact a case?

It can lead to contamination and loss of relevance.

What should be done if items in a crime scene need to be preserved?

Protect, preserve, and collect physical evidence as needed.

What are the main considerations for packaging firearms as evidence?

Prevent movement and do not package loose ammunition with firearms.

What is the significance of evidence integrity in investigations?

It ensures the reliability and admissibility of evidence in court.

What must be done when releasing a crime scene?

Conduct a final survey and document the release.

How should digital evidence be handled to prevent damage?

Use non-static packaging and avoid extreme conditions.

What defines a clandestine lab?

An unlawful operation for manufacturing controlled substances.

What consequences can result from improperly obtained evidence?

It may be excluded from trial under the exclusionary rule.

What is important to remember about collecting DNA evidence?

Avoid using plastic packaging and refrigerate liquid samples.

Why should background contexts be considered in evidence collection?

To maintain the probative value and integrity of the evidence.

What type of evidence links a crime to its victim?

Physical evidence that establishes a connection.

What happens to evidence once a crime scene is formally released?

Re-entry may require a warrant.

How should firearms be recorded upon collection?

Record details like caliber, make, model, and location found.

What is the role of forensic evidence in court cases?

Forensic evidence helps establish facts and verify testimonies in legal proceedings.

What is the chain of custody?

The process of maintaining and documenting the handling of evidence to ensure its integrity.

Why is meticulous documentation critical in evidence handling?

It preserves the credibility of evidence and aids in legal scrutiny.

What is the admissibility of evidence?

The legal rules dictating which evidence can be considered by a jury.

What rights do defendants have regarding evidence?

Defendants have the right to access and contest evidence presented against them.

What are the consequences of mishandling evidence?

Mishandling can lead to contamination or exclusion of evidence during trials.

What is the significance of Miranda rights in evidence collection?

Miranda rights protect a suspect's right against self-incrimination during police interrogations.

What are common types of evidence in court?

Witness testimonies, physical evidence, documentation, electronic evidence.

What is a search warrant?

A legal document authorizing law enforcement to search a specified location for evidence.

What does presenting evidence in a chain of custody involve?

Showing all personnel who handled the evidence from collection to trial.