SACRAMENTO (AP) -- California Attorney General Jerry Brown says his office is helping Los Angeles police investigate the possible involvement of prescription drugs in Michael Jackson's death.

The Bureau of Narcotic Enforcement is searching the state database that tracks doctors who prescribe controlled substances. It also monitors the quantity and recipients of those drugs.

Brown told The Associated Press Thursday the records search will be a critical part of the investigation.

He says the same database helped investigators in the death of former Playboy centerfold Anna Nicole Smith.

Brown says his employees will watch for aliases as they help investigate Jackson's death.