A school board president accused of attacking his estranged wife claims he was on Ambien and doesn't remember the incident.

Brent Walden was arrested on February 19, one day after Bennett, Colorado. Police say he broke into his estranged wife's home.

Police say he attacked both her and a male friend who was there.

When entering his defense in Thursday's preliminary hearing, Walden said he had taken Ambien that night and does not remember going to his wife's home.

Walden says he and his wife separated on December 15 and he had been taking Ambien since then to help him sleep.

Walden does not deny the incident happened, but says he has no recollection of it.

"The scary part about Ambien is, you don't know. I didn't even know that was a side effect or a possibility," said Walden.

According to Walden, there have been times where he had woken up after taking Ambien where his keys and shoes had moved, and he even found himself sleeping in another location.

He is no longer taking Ambien, but says he is on a different medication.

During the encounter at his wife's home, Walden was injured and suffered a black eye.

In the police report, it says just before Walden left his wife's home, he apologized and shook hands with her male friend.

Walden says he was called by his father-in-law the day after the incident to tell him police were looking for him.

His wife says since she left him in December, he has been harassing her. She also claims he was harassing her earlier in the evening on February 18 before the incident.

Walden faces charges of second-degree burglary, third-degree assault and first-degree criminal trespass.

He is the Bennett School Board president and says he hopes he can stay in the position.

"I do believe that everything I've ever done on the school board has been honorable and respectable," said Walden.

Walden's attorney says they may join a class-action lawsuit involving Ambien.