Question for those in law enforcement.

How long does it take to determine that a death is in fact, a suicide, and not murder? Do they even investigate when they discover someone hanging from the rafters?? If so, how long does the investigation take? 5 minutes? 24 hours? A week? A month?

• It's very easy to tell the difference between a murder and a suicide, so They do not investigate unless the person hanging has enemies.