Which method is NOT effective for locating witnesses not present at the crime scene?

Interviewing bystanders is not an effective method for locating witnesses who were not present at the crime scene. This approach relies on individuals who happened to be nearby at the time of the incident, but it does not expand the search for witnesses beyond those who witnessed the event directly.

In contrast, canvassing the area actively searches for people who may have information, regardless of whether they witnessed the crime at that moment. Media broadcasts can reach a broader audience, potentially bringing forward witnesses who may have seen or heard something related to the case. Confidential witness programs are designed specifically to encourage individuals who have information to come forward without fear of repercussion, making them an effective means to identify and locate witnesses.