Friends:

The Irvine neighborhood Quinton “Rampage” Jackson calls home is quiet.

Lawns are green and well-kept, kids play in the streets, and parents walk their dogs in the afternoon. By all accounts, Jackson’s demeanor, outside of the Ultimate Fighting Championship octagon he fought in, fit the neighborhood — “he’s quiet, he’s calm, he’s cool,” neighbor Andrew Kreger said.

The sign above Jackson’s doorbell reads “As for me and my house, we will serve the Lord.”

Even with his ostentatious, raised Ford F-350 pick-up truck painted in a green-and-gray camouflage pattern with his imposing figure on the side, many neighbors didn’t know his name or what he did for a living.

So when Costa Mesa police chased who they believe was Jackson Tuesday from Newport Boulevard and 18th Street three miles south into Newport Beach while running red lights, driving on sidewalks and into oncoming traffic all on only three good tires, many close to him ask, why?

“I think he just snapped. He had a nervous breakdown,” said Paul Foster, a friend and fellow trainer at Huntington Beach’s Ultimate Training Center. “Normally, he’s 99.9% under control. Everybody loses control at one time or another. But not everybody’s around to see it.”

The spotlight has been brighter on Jackson than ever before, Foster said. Jackson was a coach on the latest season of SPIKE TV’s “The Ultimate Fighter” reality series and was upset, or as Foster said “robbed,” in a high-profile light heavyweight fight against Forrest Griffin on July 5 in Las Vegas.

“Now he’s known on TV, before he was known only in the fight world,” Foster said. “[Tuesday] was a five-minute tantrum.”

Costa Mesa police said Jackson was cooperative and calm Tuesday night as he waited to be bailed out. Irvine police said he was equally passive Wednesday afternoon when they took him to a hospital for a mental health evaluation after his friends flagged down a passing police car.

Neighbors said at least half a dozen police shut down Jackson’s street, Whistler Isle. Police were inside the house with him for two to three hours, neighbors said. In the end, police deemed him a potential threat “to himself and others,” Lt. Rick Handfield said.