May 28, 2013 -- As I Lay Dying lead singer Tim Lambesis is set to appear in court Wednesday, weeks after allegedly hiring a hitman to kill his estranged wife. Lambesis' lawyers are expected to lay out a "roid rage" defense, blaming the rocker's steroid use to his alleged attempt to arrange the murder.
Thomas Warwick, the rocker's lawyer, says Lambesis was mentally unstable when he asked an undercover detective to kill his wife and that the singer's thoughts were "devastatingly affected" by the drugs.
"His thought process was dramatically impacted by the steroid use," Warwick said in a Vista, Calif., courtroom on May 17 during a bail hearing.
Lambesis, 32, was arrested May 7 in Oceanside, Calif., and charged with soliciting the murder of his wife Meggan Lambesis, who resides in Encinitas, Calif. Tim Lambesis remains behind bars on $2 million bail and has pleaded not guilty.
Prosecutors don't buy the "roid rage" defense and say the singer knew exactly what he was doing and his estranged wife now lives in fear.
"She is living petrified, not knowing, 'Can I come out, who else is out there?'" Deputy District Attorney Claudia Grasso said.
Once Lambesis began working out, the steroid use began and the singer known for his head-banging music with a Christian twist lost his faith in God, Warwick said.
A 2008 video of Lambesis on the television show "L.A. Ink" shows a much skinner body compared with a 2013 video of the rocker working out in the gym on his personal YouTube page.
"Anabolic steroids lead to an increase of testosterone hormone in blood, but it is very complex and it is not a direct cause-and-effect scenario," ABC News senior medical contributor Dr. Jennifer Ashton said.
Authorities began investigating Lambesis about a week prior to his arrest after they said they got word he was allegedly trying to find someone to kill his wife at a local gym. Grasso said Lambesis later met with the undercover agent posing as a hit man and gave him $1,000 and instructions on how best to kill his wife.
Meggan Lambesis served her rocker husband with divorce papers in September 2012, according to court records. The couple has three adopted children from Ethiopia.
Tim Lambesis is a founding member of the metalcore band that formed in 2000 in San Diego. As I Lay Dying's 2007 album "An Ocean Between Us" hit number 8 on the Billboard 200, and no. 1 on the Top Rock chart. The group was nominated for a 2008 Grammy Award for the song "Nothing Left" from the album. The band has released six albums.
ABC News' Kevin Dolak contributed to this report.