His step-brother Thomas Morphey has told the Chicago Sun Times that he believes Peterson killed Stacy.
Morphey also says he thinks he unwittingly helped Peterson dispose of the body. It's been reported that Morphey was offered immunity by the will county state's attorney seventeen months ago.
Peterson's attorney says the fact that Morphey has not been called to testify indicates the state's attorney doesn't believe he is a credible witness.
"Tom Morphey has a documented history of mental illness, suicide attempts, psychiatric admissions, alcoholism and drug addiction," said Joel Brodsky, Drew Peterson's attorney.
The state's attorney's office refused to comment on whether Morphey had been offered immunity.