Criminal Investigation Fundamentals Flashcards

What is the primary purpose of maintaining a strict chain of custody for physical evidence collected at a crime scene?

Answer: To document every person who handled the evidence, ensuring its integrity and admissibility in court.

The chain of custody is a legal and procedural requirement that tracks the chronological possession and handling of an item of evidence from collection to its presentation in court. This documentation proves the evidence has not been tampered with, substituted, or contaminated, which is crucial for its admissibility and for proving its integrity.

An officer is speaking with a witness who saw a vehicle flee the scene of a theft. The officer is asking non-accusatory, open-ended questions to gather information. Which term best describes this interaction?

Answer: Interview

An interview is a non-accusatory, conversational process designed to gather information from a witness, victim, or other person with knowledge. An interrogation, by contrast, is typically accusatory, involves a suspect, and is designed to elicit a confession or admission of guilt.

Which of the following best defines the legal principle of *corpus delicti* in a criminal investigation?

Answer: The principle that a defendant's confession, by itself, is not sufficient for a conviction without proof that a crime actually occurred.

*Corpus delicti*, Latin for "body of the crime," is the principle that the prosecution must prove that a crime was committed before a person can be convicted of that crime. It prevents convictions based solely on a defendant's confession without any independent evidence that a crime actually happened.

An officer observes an individual late at night in a high-crime area, peering into multiple parked cars and trying door handles. The officer has not seen a crime committed but stops the individual to ask what they are doing. What is the minimum legal standard required for this temporary stop, known as an investigative detention?

Answer: Reasonable suspicion

Based on the landmark case *Terry v. Ohio*, an officer can conduct a brief investigative detention (a "Terry stop") if they have reasonable suspicion, based on specific and articulable facts, that criminal activity is afoot. This standard is less than probable cause but more than a mere hunch or guess.

In the Pennsylvania criminal justice process, what is the primary purpose of a preliminary hearing?

Answer: To determine if the Commonwealth has sufficient evidence to establish a *prima facie* case against the defendant.

The preliminary hearing is a pre-trial stage where a Magisterial District Judge hears evidence from the prosecution to determine if there is a *prima facie* case—enough evidence to believe a crime was committed and that the defendant likely committed it. If this standard is met, the case is held for trial in the Court of Common Pleas. It is not a trial to determine guilt or impose a sentence.

At the scene of a burglary, an investigator collects a pry bar, takes photographs of a footprint, and obtains a written statement from a neighbor who saw the suspect. Which of these items is considered testimonial evidence?

Answer: The written statement from the neighbor

Testimonial evidence is evidence given by a witness in the form of a statement, either spoken or written, under oath. Physical evidence (also called real evidence) consists of tangible items like the pry bar or the broken door. The photographs are a form of demonstrative evidence that illustrates the physical evidence.