From TMZ.com:

Sources say last night an Irvine police car was waved down by people near the place Rampage was staying who said he was acting weird. This, of course, following the insane chase the day before in which the UFC fighter hit several cars in his monster truck and was arrested at gunpoint.



We're told Irvine cops saw Rampage, deemed him a danger to himself and others, and took him to a hospital for observation.



Cops won't officially confirm if it's a psychiatric hold.

BloodyElbow.com is trying to confirm if this is true or not. Stay tuned. Props to the folks in the FanPosts for being on top of this.

Mike Chiapetta has the scoop:

Former UFC light-heavyweight champion Quinton "Rampage" Jackson was admitted to a hospital on Wednesday for a mental health evaluation following an incident in which he was exhibiting "unusual behavior," Irvine, Calif., police Lt. Rick Handfield told NBCSports.com on Thursday. This incident came on the heels of Tuesday's arrest following a car chase in Costa Mesa, Calif. Handfield said that a passing officer was flagged down on a city street at about 4:30 pm on Wednesday, and one of the people at the residence who was an acquaintance or relative of his told police they were "concerned about some alarming statements and unusual behavior he was exhibiting." The responding officer spoke to Jackson, who was cooperative, and officers detained him and transported him to a local hospital for a mental evaluation. Handfield said Jackson is not being charged with any crime, and was considered a "mental health detainment." Jackson's present status is unclear, as California's HIPAA laws guarding medical privacy preclude police from giving any further information. UFC did not immediately return calls for comment.

[UPDATE] by Nick Thomas - Dana White's first interview since the Rampage arrest (KLOS in L.A.) (7/16):

[UPDATE] by Michael Rome - Dave Melter has the details:

According to Lt. Rick Handfield of the Irvine, CA, police department, an officer was pulled over while driving past Jackson's house in the city, and a friend of Jackson's asked for help. He told the officer he was worried about the fighter's behavior. The officer made contact with Jackson, evaluated him, and asked him to come to the hospital for observation. Jackson was completely cooperative with the officer at all times. Due to HIPPA laws, the department is not allowed to release any information about what the evaluation entailed or discovered.

From what I can tell, a friend was worried about his behavior and wanted police to check his mental health. It's a far cry from an arrest.