At the time of the arrest, Brown was on probation in a felony assault case for attacking pop star Rihanna hours before the 2009 Grammy awards. The arrest led a judge in California to revoke his probation, and he was ordered in May to serve an additional 131 days in jail. He was released in June.
Brown's attorney, Danny Onorato, argued that Brown had already suffered extensive consequences from the Washington case, noting the additional jail time in California and the four months he spent receiving inpatient counseling. He said that Brown's career has been on hold for nearly a year and that he wanted to take responsibility for his actions so he could go back to work, including a tour in support of a new album.
"To say that he's been punished severely in this matter is an understatement," Onorato said.
Brown spoke only briefly, saying: "I would like to say to the court that I'm sorry." He did not comment as he left court, swarmed by photographers and a handful of fans.
Brown had previously pleaded not guilty in the case. A trial scheduled for April was delayed, and two previous attempts to reach a plea deal fell through. Oronato said there were "nuances" of difference in the potential deals.
"As Chris Brown himself has now finally acknowledged, he punched a man in the face without provocation," U.S. Attorney Ronald Machen said in a statement. "No matter your status or celebrity, you will be held accountable for such conduct in our city."
Brown had a squeaky-clean image before his attack on Rihanna, but since then he has had several flare-ups that have been reported to authorities and noted by Los Angeles prosecutors. Brown broke a window after a 2011 "Good Morning America" interview in New York and was accused of snatching a woman's cellphone in Miami after she tried to snap pictures of the singer. He was also slightly injured in a New York nightclub brawl and, earlier this year, was accused of being involved in a fistfight with Frank Ocean's entourage over a parking spot at a West Hollywood recording studio.
He was not charged in any of the incidents, but they have hurt his public standing. Nonetheless, legions of fans, including many of his more than 13 million Twitter followers, continue to support him. Following the hearing, he tweeted "(hash)XTheAlbum," a reference to his new recording, due out Sept. 16.
Oronato said his client has learned to "be more judicious" in his dealings with the public.
"He's an incredibly talented and charismatic kid," Oronato said. "I think he's misperceived a lot. He's a wonderful person, and I'm glad this is behind him."
Brown's bodyguard, Christopher Hollosy, was convicted of misdemeanor assault in April for his role in the same scuffle. He has not yet been sentenced. The victim, Adams, has also filed a $1.5 million lawsuit against Brown and Hollosy.
Follow Ben Nuckols on Twitter at https://twitter.com/APBenNuckols.