Yes, it is. Many books titled 'A Killer Among Us' are often based on true crime stories, which detail real - life events of a killer's actions and the subsequent investigations.
It's hard to say for sure. Different people might have different interpretations of the true story. Maybe it's based on real events but with some fictional elements added for drama.
Sure. The movie is based on a true story. It aims to bring to light the chilling reality of such incidents and might have added fictional elements for dramatic effect.
In many cases, 'A Killer Among Us' on Lifetime does draw from true stories. The show might take some liberties for entertainment purposes, but the core elements have roots in reality.