Former Littleton police officer Jeffery Johnston pleaded guilty to one drug-trafficking charge and one gun-possession charge in federal court Monday.
The FBI arrested Johnston at his home in Parker on July 19 after Johnston purchased about 16 grams of Ecstasy from an informant.
After Johnston was taken into custody, federal agents searching his home allegedly found cocaine, steroids, hundreds of prescription pills, several firearms and ammunition, along with tools used to portion and distribute drugs.
Johnston will be sentenced Feb. 3. He is facing up to 20 years for intent to distribute and up to 10 years for being a prohibited person in possession of firearms.