Source: Chicago Tribune Wire

Chris Brown was arrested moments before the 2009 Grammy's were set to commence. The Los Angeles police department announced that Chris Brown, a double nominee and scheduled performer, was being investigated for allegedly assaulting an unidentified woman the night before. Brown turned himself in to authorities and was briefly held before posting $50,000 bail Sunday night, jail records showed.

Chris Brown and longtime girlfriend Rihanna also nominated, were both slated to perform in different slots of the show, but separately dropped out at the last minute. The couple were due to perform at the Grammy awards last night but they pulled out after Brown, 19, was accused of attacking a woman after an argument in a car. Police have not named the woman involved in the incident, reported to have suffered "visible injuries", but the Los Angeles Times reports witnesses claiming that the woman was Rihanna.

Police booked the 19-year-old R&B singer and dancer on suspicion of making a criminal threat, a felony. Police did not explain how their initial report of an injury assault related to the charge, but it will ultimately be up to the district attorney's office to decide what charges, if any, should be brought against Brown.