| LOS ANGELES
LOS ANGELES Singer Chris Brown was arrested and charged with making criminal threats on Sunday for an early morning attack on an unidentified woman widely thought to be his girlfriend, pop star Rihanna.
Los Angeles police would not confirm the name of the victim, but both Brown and Rihanna missed their performances at Sunday's Grammy Awards, and several media outlets speculated that Rihanna was the unidentified woman.
Brown, 19, was scheduled to perform his love song "Forever" at the music awards ceremony in Los Angeles on Sunday evening, and Rihanna was set to sing her hit single "Disturbia."
Neither Rihanna, who was nominated in three categories, nor Brown, who was nominated twice, walked the red carpet, and they were not in attendance for the awards ceremony. Their representatives could not be reached for comment.
As the show was getting underway, Brown turned himself in for questioning by police. Later, he was booked on a charge of making criminal threats and released on 50,000 bail, according to a Los Angeles Police Department statement.
Brown was being investigated for alleged domestic violence felony battery, and additional charges could be filed after officials review the case, the LAPD said in its statement.
Rihanna canceled her performance shortly before the Grammys started, the National Academy of Recording Arts and Sciences said.
"We have just been informed that Rihanna will not be attending tonight's 51st Annual Grammy Awards. We're sorry she is unable to join us," the academy said. There was no further explanation for her absence.
Soul legend Al Green performed alongside pop star Justin Timberlake in Rihanna's place.
Grammy officials made no mention of Brown's performance but he did not appear on stage as scheduled.
Police said Brown got into an argument with an unidentified woman while sitting in a parked car in the city's Hancock Park neighborhood at around 12:30 a.m. on Sunday.
"After stopping his car, Brown and the woman got out and the argument escalated," the police said. "The woman suffered visible injuries and identified Brown as her attacker."
Police received a 911 call reporting the disturbance and according to the statement, when officers arrived they found the victim, but Brown had already left the scene.
Brown, who broke onto the Billboard charts at the age of 16 with his hit single "Run It" and sold 2 million copies of his self-titled debut album, also scored a pair of hits on his sophomore effort, "Exclusive," in 2007.
Barbados-born Rihanna also released her debut album in 2005 and had a number one hit single with "SOS" less than a year later. She followed with three more number ones: "Umbrella," "Take a Bow" and "Disturbia."
She won a 2007 Grammy Award for her single "Umbrella," a collaboration with the rapper Jay-Z.
(Additional Reporting by Bob Tourtellotte; Editing by Sandra Maler)