LOS ANGELES (AFP) - R&B singer Chris Brown was charged with assaulting his pop-star girlfriend Rihanna here Thursday as gruesome details about the alleged attack emerged for the first time. Brown, 19, appeared in court for arraignment on the charges, which came after he allegedly subjected Barbados-born "Umbrella" singer Rihanna to a savage beating in the early hours of February 8. The incident shocked the music world and left Rihanna nursing cuts and bruises to her face, forcing her to cancel a scheduled performance at the Grammy Awards in Los Angeles later that day. Brown is charged with felony counts of assault and making criminal threats, a statement from the Los Angeles County District Attorney's office said. If convicted on all counts, Brown could face a sentence ranging from probation to four years and eight months in state prison, a spokeswoman for the district attorney's office said. Brown's arrival at Los Angeles Superior Court Thursday was greeted by a scrum of media who swarmed all over the star and his entourage as he attempted to enter the building. Inside the court he did not enter an plea as a trial judge granted a request to adjourn the case until April 6. Speculation had mounted over whether Brown would face charges over the incident after he and Rihanna reportedly reconciled over the weekend. Brown had issued an apology for the incident on February 15, saying he was "sorry and saddened" by the events and that he was seeking the counseling of his pastor, family and friends. "Words cannot begin to express how sorry and saddened I am over what transpired," Brown said in the statement. "I am seeking the counseling of my pastor, my mother and other loved ones and I am committed, with God's help, to emerging a better person." The Los Angeles Police Department has steadfastly refused to divulge specifics in the case, but details emerged Thursday in a detective's affidavit that gave a blow-by-blow account of the incident. The account revealed how Brown allegedly lashed out at Rihanna as the couple drove home from a pre-Grammys party in his rented Lamborghini. The affidavit said the attack was triggered after Rihanna had read out a lengthy text message from an unidentified woman found on Brown's phone. The singer reportedly slammed Rihanna's head against the window of the car before repeatedly punching and biting her. The affidavit said Rihanna's mouth filled with blood, which was splattered across the interior of the car. Brown is also alleged to have attempted to push Rihanna out of the moving car before warning: "I'm going to beat the shit out of you when we get home." When Rihanna called her assistant to alert police, Brown raged: "You did the stupidest thing ever. I'm going to kill you" before putting the singer in a headlock so severe she nearly lost consciousness, according to the report.