Getty

Mixed martial artist Jason "Mayhem" Miller arrives at the third annual Fighters Only World Mixed Martial Arts Awards 2010 at the Palms Casino Resort December 1, 2010.

A mixed martial arts fighter was arrested Monday morning on suspicion of breaking into a Mission Viejo, Calif., church and setting off fire extinguishers while in the nude, police said.

The church's pastor called deputies at about 9 a.m. to report that he'd found books and CDs scattered throughout the church, broken picture frames and fire extinguisher dust on the first and second floors, Orange County sheriff's spokesman Jim Amormino told City News Service.

Jason "Mayhem" Miller, 31, was found on the second floor without any clothes on, Amormino said. He was booked on suspicion of burglary.

Miller is best known as an Ultimate Fighting Championship (UFC) fighter and host of MTV’s "Bully Beatdown." Friends say they were shocked to hear what happened.

Stay informed with the latest headlines; sign up for our newsletter

"You don't expect to hear news like that coming about a friend," said Michael Guymon, martial arts fighter

Guymon is a former UFC fighter, better known as "The Joker,” and says the stress of the job can be overwhelming.

"It's harsh," Guymon said. "One second they're all for you, they all feel you, they're pumping you up and the next second they're shutting you down."

Over the weekend, Miller had a public feud on Twitter with UFC President Dana White. Some speculate the exchange, coupled with his recent retirement from the UFC, may have pushed him over the edge.

Watch the most-viewed videos on NBCNews.com

"It hurts, it hurts as a fighter," Guymon said. "They look at us, we're supposed to be all these tough guys, but deep down inside, it does get to us."

Guymon says he tried to commit suicide three years ago and was fortunate to get the help he needed. He thinks Miller's arrest may turn out to be the best thing for him.

"If it is mental illness or depression, you have people that know how to deal with what you're going through," Guymon said.

City News Service (CNS) contributed to this article.

More content from NBCNews.com:

• Big debt threatens security clearance for troops
• Wife of former congressman dies after being run over by her own car
• Report: Ex-Navy sub commander faked death to get out of affair
• Evangelist Billy Graham 'doing fine' at hospital
• Family: Cops didn't have to shoot knife-wielding man near Times Square
• Video: Multiple cameras show man driving wrong way

Follow US News from NBCNews.com on Twitter and Facebook