San Francisco’s district attorney has charged Oakland Raiders wide receiver Darrius Heyward-Bey with drunken driving following his early morning arrest on the Bay Bridge last month by the California Highway Patrol.

According to CHP spokesman Tony Tam, the Raiders first-round draft pick of 2009 was driving his 2012 Range Rover on the lower deck about 2 a.m. April 7 when an officer spotted him speeding and weaving in his lane.

Heyward-Bey, 25, was pulled over and given a field sobriety test, which he failed, the CHP said. He was cited for alleged drunken driving and later released.

It wasn’t clear where Heyward-Bey was headed at the time or where he had been. But law enforcement officials described him as “very cooperative.’’

Authorities would not say what Heyward-Bey’s blood-alcohol level was when he was arrested. A level of 0.08 percent constitutes drunken driving.

Misdemeanor citations carry a maximum six-month jail sentence, said Stephanie Ong Stillman, spokeswoman for the district attorney. Heyward-Bey was charged Thursday and is scheduled to appear in court May 31.

The former University of Maryland standout was the surprise seventh overall draft pick in 2009, taken ahead of more highly touted wide receivers such as Michael Crabtree, who went to the 49ers. The late Raiders owner Al Davis signed him to a five-year, $38 million contract.

Heyward-Bey struggled with injuries and dropped passes in his first couple of seasons before coming on strongly last year.

The Raiders issued a statement saying, “The team is well aware of the situation, and takes matters such as this very seriously. The organization will continue to gather specifics, and continue to cooperate with all parties involved.”