MALIBU, Calif.—Redmond O'Neal, the son of Farrah Fawcett and Ryan O'Neal, has pleaded guilty to possessing heroin and methamphetamine.

The 23-year-old O'Neal pleaded guilty Thursday in a Malibu court to the two felony counts and a misdemeanor count of driving under the influence of drugs. As part of a plea deal, a second DUI charge was dismissed.

He was placed on three years' probation on the misdemeanor charge and fined about $1,700.

The district attorney's office says O'Neal also was ordered to remain in drug treatment until a hearing next month to determine if he can enter a drug-diversion program on the felony charges.