Redmond O'Neal, who was caught driving with illegal drugs and a handgun in Santa Monica on Tuesday, pleaded not guilty to two felony counts on Thursday. He entered his plea in a Los Angeles court.
Earlier Thursday, O'Neal, 26, was charged with possession of a controlled substance and possession of a firearm by a felon. On Aug. 24, he will have a probation violation hearing and find out the date for a preliminary hearing.
O'Neal, son of the late Farrah Fawcett and actor Ryan O'Neal, is being held without bail.
Police arrested O'Neal at 8:45 a.m. after a motorcycle officer caught him running a red light at the 600 block of Olympic Blvd., just a few blocks away from the SMPD headquarters.
Police said O'Neal allowed authorities to search his car, at which point they found the heroin and marjuana. O'Neal is on probation stemming from a felony drug charge related to his arrest in a county jail parking lot in Castaic, Calif.
O'Neal has a history of drug problems. Previously, he was arrested for possession of heroin and methamphetamine and, in a separate incident, possession of methamphetamine.
A year ago, O'Neal graduated from a drug court program related to his previous arrests.
O'Neal is featured in the reality show Ryan and Tatum: The O'Neals, currently airing on the Oprah Winfrey Network.
City News Service contributed to this report.