ALAMEDA — The Napa police department on Friday reopened its investigation into an attack that left Oakland Raiders assistant coach Randy Hanson with a broken bone in his face.

Hanson was hospitalized following the Aug. 5 attack that he told police was initiated by a member of the Raiders coaching staff at the team’s training camp hotel in Napa. Internet reports said head coach Tom Cable attacked Hanson during a meeting with some of the team’s defensive coaches.

Cable would not comment when asked Friday about the news that the police had reopened the investigation. Earlier in the week, he said “nothing happened.”

“When all the facts come out, everything will be fine,” Cable said Thursday.

The police said earlier this week that the case was closed because the victim was unwilling to cooperate. On Friday, the department announced that it had been reopened, apparently after Hanson agreed to cooperate with authorities.

Messages left for Hanson at the Raiders headquarters in Alameda and for Hanson’s San Francisco-based attorney, John McGuinn, were not immediately returned.

The NFL is already looking into the case to determine if Cable violated the league’s personal conduct policy. According to the policy, a coach or player can be disciplined for “violent or threatening behavior among employees, whether in or outside the workplace.”

According to the Internet site the National Football Post, the attack happened after Cable told Hanson he was being relegated from an on-field coach with defensive backs to breaking down film.

The report said Cable attacked Hanson after the assistant verbally contested something defensive coordinator John Marshall had said.

After being told by owner Al Davis that he could not get his old job back, Hanson reportedly decided to cooperate with police in the investigation.

Hanson was also a key player in the dispute that helped lead to coach Lane Kiffin’s firing last season. Kiffin suspended Hanson after the assistant criticized the coaching staff in a meeting following a 41-14 season-opening loss to Denver. Davis later reinstated Hanson and Kiffin was fired a few weeks later.

While coach attacks in the NFL are rare, they are not unprecedented. In 1989, Buffalo Bills assistants Tom Bresnahan and Nick Nicolau got into a fracas while watching game film.

Nicolau decked Bresnahan with a solid uppercut, grabbed Bresnahan in a headlock and drove his head through a wall in the team’s administration building.