Dennis Rodman, no stranger to the cops, is being investigated by the Orange County Sheriff’s Department for sexual battery of a female patron at a local bar.

TMZ has learned the Orange County Sheriff’s Department is investigating the incident, which allegedly took place at Hennessy’s Tavern in Dana Point, near Laguna Beach. One source says the ex-basketball star allegedly slapped the woman’s rear so hard, it left a “major mark.”

The sex crimes unit is deciding whether there will be charges for the spanking.  If they lock up Rodman for this, it would be like Al Capone going to prison for tax evasion.