[Final Update - 9:20 PM PST: The LA Times now reports that, according to LAPD sources, Brown turned himself in to  authorities this evening and was booked  at the Wilshire Division station on "suspicion of making felony criminal threats in connection with an incident involving his girlfriend, pop singer, Rihanna."

He was accompanied by his attorney Mark Geragos and Geragos' investigator Scott Ross and entered the station through a back door entrance.

HitFix spoke to entertainment lawyer Russell Wetanson of Popsquire who says California state law will take any action against Brown out of the Grammy winning Rihanna's hands.

"Although the victim allegedly reported Brown to the police, many couples involved in incidents of domestic violence tell different stories the next day," Wetanson says. "This is exactly why California authorities and courts have taken the decision to prosecute such crimes out of the hands of the alleged victims. Nonetheless, if the victim does not cooperate or provide supporting evidence, the prosecution’s job becomes more and more difficult."

HitFix will continue following this story if and when events warrant it.

Update: The LA Times reports that according to sources familiar with the investigation, the LAPD plan on detaining R&B singer Chris Brown for questioning in connection with the alleged domestic violence assault against his girlfriend, pop superstar Rihanna.

The alleged incident is being investigated as a felony domestic violence case.  It was reported about 12:30 A.M. Sunday in Hancock Park.

The couple were apparently in a car together and got into an argument on North June Street, an area directly south of Paramount Studios in Los Angeles,
according to a Los Angeles Police Department statement. Brown stopped the car, the two got out, and the argument escalated, according to police.

A witness called 911, but Brown was gone when officers arrived at the scene. The woman suffered visible injuries and identified Brown as her attacker, according to police.

Rihanna's publicist issued a statement saying: "Rihanna is well. Thank you for your concern and support.”  Brown's record label has not been available for comment.

Both stars were scheduled to appear at the 2009 Grammy Awards tonight.  Shortly before the show began at 5 p.m. at Staples Center, Grammy officials issued a statement saying, "We have just been informed Rihanna will not be attending tonight’s 51st Grammy Awards. Rihanna will not be performing. We are sorry to see she is unable to join us this evening.”

More updates as warranted.]

LOS ANGELES (AP) - A pall was cast over the Grammys on Sunday night when police said just 90 minutes before the show began that they were investigating nominee Chris Brown for allegedly attacking a woman the night before. And minutes before U2 opened the the telecast with its new single, the Recording Academy said Rihanna, Brown's longtime girlfriend, had scratched her performance.

A police statement said the 19-year-old Brown had argued with an unidentified woman Saturday night, and that the fight escalated when they got out of a vehicle in the ritzy Hancock Park neighborhood. The woman told authorities that her attacker was Brown, who was not at the scene.

A CBS promotion for the upcoming show touted the R&B singer and dancer as a performer just minutes before it began, though he had not been spotted at the Staples Center as of late Sunday afternoon. A representative for Brown had no comment when approached at the venue.

Brown has long been dating pop superstar Rihanna, who was slated to perform early in the show. But she dropped out, the Recording Academy said in a statement less than an hour before the show, and she was not seen at the venue as the show was about to get under way.

"We're sorry she is unable to join us this evening," the statement said. It did not provide details as to why.

Rihanna was supposed to sing "Live Your Life/Disturbia" as the second performance of the night, Brown was later to sing "Forever."

Brown and Rihanna were both nominated in the pop collaboration with vocals category, Brown for "No Air" with "American Idol" champion Jordin Sparks; and Rihanna for "If I Never See Your Face Again" with Maroon 5.

Brown was also nominated for male R&B vocal performance for "Take You Down."


AP reporters Natalie Rotman, Beth Harris and Jacob Adelman contributed to this story. 

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