Story highlights Robert Downey Jr. spent time in prison for drug-related convictions

The "Iron Man" actor was one of 91 people who received a pardon from Gov. Jerry Brown

(CNN) Robert Downey Jr., who spent time in prison in the late 1990s for drug convictions, received a full and unconditional pardon on Thursday from California Gov. Jerry Brown.

The "Iron Man" actor was one of 91 people who received a pardon from Brown -- mostly for minor drug offenses -- in what has become an annual Christmas Eve tradition in the governor's office. The individuals completed their sentences and have been released from custody for more than a decade without further criminal activity, according to the governor's office.

People convicted of a crime in California may apply to the governor for a pardon. Applicants must receive a court order declaring he or she is rehabilitated and show they have lived "productive and law-abiding lives following their conviction," according to the governor's office.

"Pardons are not granted unless they are earned," the governor said in a statement.

Downey was convicted in 1996 of possession of a controlled substance, carrying a concealed weapon in a vehicle with a prior conviction, driving under the influence and use of a controlled substance. It was a time in his life when his substance abuse and brushes with the law overshadowed his acting talents.

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