Someone You Thought You Knew

Someone You Thought You Knew is an American documentary which aired on Investigation Discovery. The series premiered on August 2, 2018.

In homicide cases, it’s seldom strangers you need to worry about, it’s those closest to you. Even when the killing appears to be random, there can be something more sinister lying beneath the surface: a calculated plot, set in motion by someone close; someone hiding in plain sight; or someone leading a double life. What if the killer could be SOMEONE YOU THOUGHT YOU KNEW?