AUBURN — A Massachusetts man was arrested Tuesday night after police stopped a ride-share car and found him inside with a loaded handgun, cocaine, fentanyl and other items related to drug trafficking, investigators said Wednesday.

Jaysin Pedro Selter-Luna, 20, of Dorchester, was arrested on a slew of charges, including two counts of aggravated drug trafficking, two counts of drug possession and carrying a concealed weapon while under the age of 21.

He was also charged with criminal simulation for carrying a firearm with the serial number filed off, police said, and with failing to provide police with correct personal information.

The drug trafficking charges are considered aggravated, police said, because Selter-Luna was caught with a gun related to drug trafficking within 1,000 feet of Chestnut Street Park, a designated “safe zone.”

Police said that in addition to 28 grams of cocaine base and 54 grams of fentanyl, they also found $1,100 in suspected drug proceeds, a digital scale and a loaded spare magazine for the handgun Selter-Luna was carrying.

The traffic stop occurred a short distance from 114 Hampshire St., police said, a location that had been under surveillance by the Auburn Police Department’s Proactive Community Enforcement Unit. Police had been watching the residence after hearing reports of drug trafficking at the building, according to a news release.

About 6:45 p.m. Tuesday, investigators saw a man get into a car that later proved to be operated by an Uber driver. The car was stopped, police said, and Selter-Luna was found in the back seat.

Police, with the assistance of the Maine Drug Enforcement Agency, later searched the building at 114 Hampshire St. where investigators said they seized additional drugs and ammunition.

Selter-Luna remained at the Androscoggin County Jail on Wednesday.