When Ryan Edwards welcomed a new neighbor to the community, he had no idea that serial killer Stephen Port would go on to murder four young men.

In 1979, US army medic, Billy Joe Capshaw, was stationed in Germany; he had no idea that his roommate was a notorious serial killer named Jeffrey Dahmer; Billy was raped and beaten by Dahmer but he somehow managed to live to tell the tale.

Jane Carson Sadler was in bed with her young son when she went to investigate a noise in her California home; Joseph James D'Angelo, the notorious Golden State Killer, was lying in wait; Jane was brutally raped but survived.

David McVicker was unaware he'd climbed into the van of murderer William Bonin when he hitchhiked home at 14 years old; David survived but was left scarred.

Sharon Wood was unaware that shoe fetish killer Jerome Brudos was stalking her; Sharon survived an attack at gunpoint, but Brudos would kill the next day.

David Crampton's infant son Paul almost dies three times while in a hospital ward; no one knows that nurse Beverley Allitt is responsible -- she killed four babies.