Michael Kelly Michael Kelly

Does it take a killer to catch a killer? CBS' Criminal Minds: Suspect Behavior may try to answer that question. 
One of the team members on the Criminal Minds spin-off, John "Prophet" Sims (Michael Kelly), was convicted and served time for murder. But as his nickname suggests, he's reformed.
"Self-defense put him in prison — he killed a child molester," Kelly tells TVGuide.com. "In prison, Prophet finds God and becomes a good man."

See photos from Criminal Minds: Suspect Behavior

Audiences first met the Suspect Behavior team when they were called in to help the BAU solve a crime on an episode of Criminal Minds last season. In the spin-off, Kelly stars alongside Academy Award winner Forest Whitaker (team leader Sam Cooper), Janeane Garofolo (Beth Griffith), Matt Ryan (Mick Rawson), and Beau Garrett (Gina LaSalle). Richard Schiff is FBI director Jack Fickler, while Minds' technical analyst Penelope Garcia, played by Kirsten Vangsness, periodically crosses over.

Watch more celebrity interviews

Although the formula of the CBS spin-off remains the same as its predecessor, Kelly calls his team a "grittier bunch" and says fans of the original series or newcomers alike will enjoy the new show, which premieres tonight at 10/9c.

Watch the full interview: