Question

2. While investigating a murder scene, police gather evidence that includes a dead body riddled with stab wounds, fingerprints on a bloody knife found near the body, and a ticket stub from a theater several miles away from the scene. Investigators determine that the knife belonged to the victim, but matched the prints on the knife to an acquain- tance of the victim. When questioned, the acquaintance claims he was at the movies at the time of the murder—the same movie shown on the stub found at the scene. What direct physical evidence connects the acquaintance to the crime scene? What circumstantial evidence connects him to the scene? What can you conclude about the acquaintance’s involvement solely from direct physical evidence and deductive reasoning? What might you conclude, considering circumstantial evidence and inductive reasoning as well?

Answer 1

In the above case, the fingerprints found on the knife belong to the acquaintance of the victim. This fact is unquestionable. This provides physical proof for the murder scene and requires no other reasoning or inference with it. Hence, it is a piece of direct physical evidence for the crime committed. However, a ticket stub for a movie found near the dead body provides probability (but not confirmation) for the presence of the acquaintance. Put together with the fingerprints, this evidence gains weight and requires logical reasoning so as to prove a particular statement. This is called Circumstantial or Indirect evidence. Since the fingerprints are direct physical evidence, proves that the acquaintance was present at the murder scene. By Deductive or Top-Down reasoning, this statement(premise) leads to the above conclusion. Combined with the presence of the ticket stub near the dead body which has the same time as the murder(the acquaintance would have carried it in order to enter the theater). This stub presence alone makes it highly probable that the acquaintance was indeed present at the time of the murder. By all the above pieces of evidence, it can be inferred that the acquaintance was indeed present at the murder scene.