Derrick Todd Lee Aka the Baton Rouge Serial Killer Stalked the Communities of South Louisiana During the Early 2000S. Lee Would Often Take Advantage of People's Kindness to Commit His Crimes. He Would Charm Women with a Smile and Then Force His Way into Their Homes Where He Would Assault Them and Then Murder Them. Oxygen's Documentary 'Mark of a Killer' Explores Lee's Crimes This Week. Lee Was Linked to Seven Deaths and Was Convicted of Two Murders. It Is Also Believed That Lee's Family Had a History of Mental Illness and His Father Had Reportedly Suffered from Bipolar Disorder and Psychosis.