A taskforce run by the Cobb County Sheriff's Office arrested Curtis Clyde Cook on Thursday and charged him with possession of marijuana and possession of a firearm.
The Marietta Daily Journal reports that the 55-year-old officer was riding in a car that was stopped by taskforce agents because it had expired tags.
During the stop, investigators said they could smell marijuana and found a bag of the drug on Cook.
Smyrna police officer Michael Smith, a department spokesman, said Police Chief Stan Hook fired Cook on Friday.
A phone listing for Cook could not be located.
It was unclear whether he had an attorney.
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