02/08/2009 at 09:15 PM EST
is under investigation for alleged domestic violence felony battery, the LAPD confirms to PEOPLE.
"The identity of the victim will not be released," said Officer April Harding. "Any victim who's involved in a domestic violence incident is entitled to confidentiality."
Officer Harding added: "If police locate Brown, yes, he's subject to arrest."
Both Brown, 19, and girlfriend Rihanna
, 20, were scheduled to perform at the Grammys, but this statement was released Sunday evening: "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 this evening."
Around 12:30 a.m. on Sunday, Brown and a woman were in a vehicle in L.A. when they became involved in an argument, according to a police statement. After stopping his car, the R&B singer and the woman got out and the argument escalated. The LAPD received a 911 call reporting the disturbance.
When officers arrived they found the victim, but Brown had already left the scene, the statement reads. The woman suffered visible injuries and identified Brown as her attacker, police say.
The LAPD is conducting an investigation into the incident.
As for why this case is being investigated as a felony and not a misdemeanor, Officer Karen Smith explained "because there was visible injury on the victim. It can be as small as a scratch or much worse, as long as injuries are visible, it's considered a felony."
Earlier Saturday night Brown and Rihanna were at the Recording Academy and Clive Davis's Pre-Grammy Gala in Beverly Hills.
When asked about Rihanna's well being, her rep told PEOPLE, "Rihanna is well. Thank you for your concern and support."
Halfway through the Grammy telecast
, the Academy sent out this statement: "We have just been informed that Chris Brown will not be attending tonight's 51st Annual Grammy Awards. We're sorry he is unable to join us this evening."
With reporting by TIFFANY McGEE