The stepbrother of Drew Peterson says he’s convinced the former police officer killed his fourth wife, and may have even tried to frame him for her murder.

“I know he killed Stacy,” Thomas Morphey told “Good Morning America” in an interview that aired Monday. “All the circumstances point to it.”

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Morphey said Peterson asked him before Stacy's disappearance, “How much do you love me? … Enough to kill for me?”

Morphey said he told Peterson that he did love him, but not enough to kill for him.

Peterson then took Morphey with him to look into renting a locker at a storage facility, Morphey said.

“I knew it wasn’t good. He was planning on killing someone,” Morphey told the talk show. “Sometimes I wish I had rented that locker just because we’d know where she was. I partially think the locker was put in my name so he could set me up.”

But Morphey said he now believes he does know where Peterson put Stacy’s body — in a blue barrel Morphey helped move from Peterson’s home to his SUV, the Chicago Sun-Times reported.

According to Morphey, after moving the barrel, Peterson then drove him home with it still in the back of his Yukon Denali and told him on arrival, “This never happened.”

“I said ‘I won’t say a word,’” Morphey told "Good Morning America."

Peterson has repeatedly denied any involvement in Stacy’s disappearance, or the death of his third wife, Kathleen Savio, who was found dead in her bathtub in 2004.

He told WIND-AM Sunday that he and Morphey visited a storage facility before Stacy vanished because Peterson needed a place to store extra tires he’d been keeping in his garage, the Chicago Sun-Times reported.

No charges have been filed in either case.

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