Final answer:
Laius' murder wasn't investigated at the time due to Thebes being plagued, shifting focus away from the murder. This, coupled with ancient societal priorities and capabilities, meant that unresolved crimes could be overlooked until they became pressing issues.
Step-by-step explanation:
The murder of Laius, the former king of Thebes in the play Oedipus Rex, wasn't investigated at the time because Thebes was struck by a plague, drawing attention away from the unsolved murder. According to the Delphic oracle, the plague was a punishment for not bringing Laius' killer to justice. In the context of the play, the investigation of Laius' murder becomes central to the story as Oedipus, the current king, vows to solve the mystery which leads to a dramatic and tragic revelation. The societal preoccupation with immediate crises, such as plagues, often overshadows other serious concerns like unsolved crimes, as illustrated in the play. It is worth noting that ancient societies had different law enforcement practices and were not always equipped to conduct thorough investigations, especially when larger immediate threats loomed over them.