When Marty arrived at the police station, he says he didn't know he was already the prime suspect in his parents' murders. Lead detective James McCready has said that Marty's reaction when police arrived on the scene raised immediate suspicion. "I think he would have been crying. I think he would have been shaken up and very upset," Detective McCready said in a previous interview. "He was sitting there with his legs crossed and his hands folded over his knees. It struck me as odd that he would be so calm and didn't appear to be upset."
Marty said he was calm because he was in shock, and he denied any involvement in the murders. After hours of interrogation, police stopped asking questions and tried a different tactic. They told Marty the hospital had pumped his father full of adrenaline and that he'd woken up and told police Marty stabbed him. After hearing this, Marty says he eventually confessed to the murder. "I was brought up [to believe] that cops don't lie," he says. "When the cops turned around and said, 'Your father said you did it,' I started to doubt myself because I knew my father would never lie. But I knew in my heart and my soul that I wasn't responsible for this."
Police say Marty told them he used a barbell and a kitchen knife to kill his mother and father.
Once the interrogation was over, Marty says he called his extended family and told them he only confessed because police forced him to.
Marty says the hostile environment of the interrogation room caused him to give a false confession. "I kept saying, 'It wasn't me,' and they kept saying, 'We don't care. Just tell us what we want to hear. We want to know it's you,'" he says. "You get to a point where you start doubting yourself ... you just want to escape that environment."