WESTPORT–Westport police arrested a Westhaven teen and three juveniles last night after stopping them in a stolen Toyota Scion, where officers also found a “ghost gun” that held a live round.

The car had been reported stolen from Branford, Connecticut, on Saturday, and Westport police were alerted that it was in the Saugatuck area at 8:52 p.m. by stationary license plate readers.

Multiple police units searched for the car until one officer spotted it driving north on Saugatuck Avenue and called for assistance.

The Toyota “continued at normal speeds with the officer following behind, not yet attempting to stop it but monitoring and reporting its direction of travel,” Westport police said in a report.

A second officer helped block the car near the intersection of Riverside Avenue and Post Road West. There police arrested Jermell Elmore, 18, and the three juveniles.

“The four occupants were ordered from the vehicle and were compliant,” the report said. “A subsequent search of the passenger compartment yielded a firearm that was located on the rear floor just below the driver’s seat.”

The gun was assembled from assorted parts and had no serial number, police said.

The juveniles were charged with larceny of a motor vehicle and conspiracy to commit larceny of a motor vehicle. They were released to parents pending future appearances in juvenile court.

Elmore was charged with larceny of a motor vehicle, conspiracy to commit larceny of a motor vehicle, illegal possession of a firearm and conspiracy to commit illegal possession of a firearm. He was unable to post $20,000 bond and was taken to Stamford Superior Court for arraignment today.