Certified Protection Professional (CPP) Practice Exam

Circumstantial evidence is considered less reliable in investigations because it relies on inference rather than direct proof. This type of evidence does not directly establish a fact, but rather suggests possibilities based on the circumstances surrounding an event. For example, if a person was seen near a crime scene around the time the crime occurred, that information alone does not conclusively prove that they committed the crime; it merely indicates that they could be connected to it, requiring further substantiation.

In contrast, direct testimony involves firsthand accounts from witnesses who observed the events in question, making it much more compelling as it provides specific details of what occurred. Physical evidence, such as fingerprints or DNA, is also considered robust, as it provides tangible proof of a connection to a crime. Documented records, like emails or transaction logs, can offer clear, verifiable information that supports claims and establishes timelines with high reliability. Each of these latter types of evidence offers a higher degree of certainty than circumstantial evidence, which is why it is viewed as less reliable in the context of investigatory work.