EXCLUSIVE

DMX is resuming his acting career, but in a role most would consider a stretch ... 'cause now he's playing Johnny Law and busting bad guys. It's called "range" in the biz.

We got this shot of DMX on the set of the upcoming film, "Chronicle of a Serial Killer" ... and he's fully embracing the role of a cop, badge and all! It's a pretty striking image, considering X's lengthy rap sheet.

The movie features Brendan Sexton as a serial murderer ... and DMX is playing Detective White, who's trying to track down the killer. Tara Reid, Eric Roberts and Aly Mang are also starring in the film.

TMZ broke the story ... Michael Madsen was booted from the cast because of his recent DUI charge, and as it turns out ... DMX was tabbed to fill Michael's shoes.

The director, Steve Stanulis, tells TMZ ... when his casting director suggested X for the role, he knew it was a perfect fit, and the rapper didn't even have to audition. Steve says he has no doubt DMX is "going to bring a different dynamic to the role."

Filming just started in New York, and Steve says he's excited to bring DMX into the fold.