Child star Brian Bonsall was arrested in March for assaulting his girlfriend.

Before being sentenced to probation for assaulting his girlfriend during a drunken melee, a former child star told a Boulder County District judge Friday that he's sober and "happy as ever."

"It's bad it had to happen this way, I guess," Brian Bonsall told Judge Lael Montgomery. "I have a much better relationship with my family and everyone around me. I've come a long way because of this case."

Bonsall, 25, played Michael J. Fox's kid brother, Andy Keaton, on the television hit "Family Ties" from 1986 to 1989, and he starred in "Star Trek: The Next Generation" in the 1990s as well as several movies. He now is in a rock band, he told the court.

Bonsall was arrested March 28 after police say he poured an alcoholic drink in Lindsey Dunavan's face as she slept, put his arm around her neck and threw her into a bed when she tried to leave their apartment on Balsam Avenue in central Boulder.

During Friday's hearing, his attorney, Paul McCormick, told the court that Bonsall was not trying to harm his longtime girlfriend but just trying to keep her from leaving. The couple checked into rehab and have been clean for five months, McCormick said.

"When sober they got along fine, but when loaded ... both participated in a violent relationship," he said.

Dunavan was initially arrested too, but was “unarrested” at the jail when she gave her statement.

Bonsall pleaded guilty to third-degree assault, a misdemeanor that carries a maximum sentence of two years in jail. Instead, in a deal with prosecutors, Bonsall received 24 months of probation on the conditions that he stay sober and attend domestic violence classes.

A 2000 graduate of Boulder High School, Bonsall has had a number of alcohol-related run-ins with the law. He has been ticketed for underage drinking in Broomfield and Boulder counties, and was stopped by police in 2001 and 2004 on suspicion of drunken driving.

“Frankly, I was pretty concerned Mr. Bonsall was out of control,” prosecutor Pete Maguire told the court. “It’s a lifelong problem Mr. Bonsall has, and I think he knows that at this point.”

Contact Camera Staff Writer Christine Reid at 303-473-1355 or reidc@dailycamera.com.