LOS ANGELES -- Chris Brown has been charged with two felonies stemming from what a police detective describes as a brutal argument between the singer and his girlfriend, Rihanna, provoked by her discovery of a text message from another woman.

Brown is expected to be arraigned April 6 on charges of assault likely to cause great bodily injury and making criminal threats. The 19-year-old R&B singer remains free on $50,000 bail.

The felony complaint handed down in court Thursday morning identifies Brown's alleged victim only as "Robyn F." Rihanna's real name is Robyn Rihanna Fenty.

If convicted, the possible sentence ranges anywhere from probation to four years and eight months in state prison, said district attorney's spokeswoman Sandi Gibbons.

According to a detective's affidavit, Brown and Rihanna got into a fight early Feb. 8 after the "Umbrella" singer checked her boyfriend's cell phone and found a text message from another woman.

Brown pulled his car over and tried to push Rihanna out, but she was still wearing her seatbelt, Los Angeles police Detective De Shon Andrews wrote. He said Brown pushed Rihanna's head against the window, punched her with his right hand, and then continued driving while hitting her, the affidavit states. He also bit his girlfriend on the ear, the affidavit states.

The affidavit was filed as part of a search warrant request for the phone records of Brown, Rihanna and her assistant.

Brown allegedly threatened to kill Rihanna after she pretended to leave a phone message with her assistant, telling her to have the police waiting at her house.

Andrews described Brown's blows as causing Rihanna's mouth to fill with blood. He also writes that Brown tried to choke Rihanna after she took the keys to his car away. Andrews wrote that Rihanna nearly lost consciousness but also tried to fight back while in the car, at one point trying to gouge at Brown's eyes.

Brown was arrested hours later and booked him on suspicion of making criminal threats. Police said at the time a woman identified Brown as her attacker during an early morning dispute in an upscale Los Angeles neighborhood.

A phone message left for Brown's attorney, Mark Geragos, was not immediately returned Thursday. Brown's publicist Tony Knight said any statement would likely come from Geragos after today's hearing.

Rihanna's spokesperson had no comment on the charges filed against Brown.

Brown issued a statement a week after the incident saying that he was "sorry and saddened" about the incident. Rihanna also later issued a statement, saying she wouldn't comment on the alleged beating at the request of authorities. She thanked fans for their support.

Brown's arrest has seriously damaged the "Run It!" singer's squeaky-clean image, and compelled sponsors to drop him or not renew his deals.

The alleged attack also came hours before the couple were scheduled to appear and perform at the Grammy Awards. Both were no-shows for event.