Michael Peterson claims after spending a night out in the garden with his wife, Kathleen, he went inside to go to bed when he found Kathleen bloody at the bottom of the staircase.

“She was crumpled up on the floor, and I picked her up, and I held her, and then I called 911,” Peterson tells Dr. Phil on Monday’s episode.

What happened to Kathleen that fateful night in 2001? Prosecutors argued that Peterson killed his wife for insurance money and because she had discovered a secret. He was convicted of murder and spent eight years in jail, but was set free in 2017. 

In the video above, Peterson, who has consistently defended his innocence, describes the night Kathleen died. And on Monday, hear about another woman whom Peterson knew who was also found dead at the bottom of a staircase. On Tuesday, hear about a bizarre theory that may hold the key to what really happened to Kathleen. Check here to see where you can watch.