DALLAS -- Cowboys defensive tackle Josh Brent will remain free while he awaits trial for intoxication manslaughter, as a judge on Friday denied a request by prosecutors to revoke his bond due to problems with alcohol monitoring.

Brent is charged in the fatal car crash Dec. 8 that killed Jerry Brown, a Cowboys practice squad player, college teammate and friend. Police have accused Brent of driving with a blood-alcohol content more than twice the legal limit.

As a condition of his $100,000 bond, Brent is required to wear an alcohol ankle monitor and appear for regular meetings with a county officer. Witnesses at Friday's hearing said he had repeatedly missed required times for his ankle monitor to download information, as well as two appointments with the officer.

Judge Robert Burns ordered a second form of monitoring to take breath samples, and for Brent to provide a urine sample. Burns said he would not increase Brent's bond amount.

Prosecutors had filed a motion Thursday asking for his bond to be revoked.

Brent's ankle monitor was set off for alcohol four times in February and March, but both sides agreed Friday that those instances were most likely caused by the presence of alcohol in the air or near Brent -- not drinking. His attorneys said they didn't know how the alcohol positives occurred, but suggested in court that they could have been triggered by things as benign as mouthwash or hand sanitizer.

Brent sat silently throughout the nearly hour-long hearing, though at times he tapped one of his attorneys, George Milner, on the shoulder and whispered in his ear. He did not testify and declined to answer questions outside court.

Heath Harris, the Dallas County first assistant district attorney, said authorities wanted to be certain that Brent wasn't drinking or doing anything to violate his probation.

"Even though ... we can't prove beyond a reasonable doubt that he was drinking, we can't prove that he was not drinking," Harris said. "That's the biggest problem."