Signs of a Psychopath (2020)

S3E4 I Killed Him. Boom. Boom.

When police arrive following a 911 call, they discover a father of two shot dead in his home, riddled with over 15 bullet wounds. As investigators interview the family, they realize one key person is absent: the mother-in-law. This leads detectives to ponder whether this seemingly innocent grandmother might actually be a ruthless killer.