Cmdr. Andy Lewis said the investigation has been submitted to the Napa County District Attorney's Office for review. Lewis would not disclose when the investigation was completed.
Cable is alleged to have assaulted assistant coach Randy Hansen at the Raiders' training camp facility in Napa at about 10 a.m. on Aug. 5. Hansen reportedly suffered a broken jaw.
Without naming Hansen as the assault victim, police said in an Aug. 21 news release that the victim was taken to Queen of the Valley Medical Center where he was met by investigators the next day.
Napa police said in August the victim did not want "any police action or formal charges filed" and refused to identify the assailant or any potential witnesses.
"Due to a lack of information provided to the Police Department, the case was closed," police said.
The case was reopened when new information came to light, police said.
Police said this morning that any additional information will originate from the district attorney's office.
Napa County District Attorney Gary Lieberstein was not immediately available for comment. A spokeswoman in his office said the case is under review.