Brown's lawyer, Mark Geragos, argued the case should be dismissed because prosecutors abused the grand jury process to prepare for trial. He says prosecutors used the grand jury to "freeze" the testimony of the alleged victim in the case.
The 24-year-old R&B singer and his bodyguard, Christopher Hollosy, are accused of punching a man outside the W Hotel in Washington, D.C. in October.
The two allegedly punched 20-year-old Isaac Parker after he tried to get in a picture the singer was taking with two of the victim's female friends. Parker suffered a fractured nose and injuries to his face and head.
On Monday, Geragos called the incident "the most investigated misdemeanor of all time."
Nevertheless, Judge Patricia Wynn concluded that prosecutors had the right to use to the grand jury to assess the strength of their case.
"I am persuaded that there was no abuse," Wynn said.
At the time of the alleged assault in Washington, D.C., Brown was on probation in California for a 2009 attack on singer Rihanna, his then-girlfriend. Soon after his arrest in Washington he entered rehab for anger management treatment, but Brown was turned over to U.S. Marshals at the Los Angeles County Jail last Wednesday after failing to stay in the court-mandated program.
Los Angeles Superior Court Judge James R. Brandlin said the facility discharged Brown for several reasons, namely, that he allegedly failed to take a mandated drug test, that he made a provocative statement during group therapy, and that he touched elbows with a female client.
Geragos said the incidents that allegedly happened in the facility were blown out of proportion.
"This client has to be the most scrutinized person when it comes to psychiatry of anybody I've ever seen," said Geragos. "He made a comment. I could go on and on about it, but what difference does it make? He was in there getting therapy, and it is what it is. Any suggestion that he didn't do testing is wrong because he did do the testing and it came back negative."
An additional hearing tied to the assault case is scheduled for Monday afternoon in Washington D.C,. The defense attorneys want Brown and his bodyguard to be tried separately.
Both are scheduled to go on trial for the assault charges on April 17. A judge will hear the case, not a jury.
If convicted in the Washington, D.C. case, Brown could face additional penalties, including time behind bars, under the terms of a court order in the Rihanna case.
Meantime, Brown has been ordered to remain in custody until the probation violation hearing scheduled for April 23 in Los Angeles.
The Associated Press contributed to this report.