AUBURN – A diamond ring valued at $5,000 is missing, but the man who allegedly stole it isn’t. He’s behind bars.

Son Thanh Nguyen, 37, of Portland is being held at the Androscoggin County Jail in lieu of $7,500 bail. He’s charged with felony theft by unauthorized taking.

Nguyen was stopped Sunday night by Maine State Police in Falmouth after Auburn police issued an alert for the car he was driving.

Auburn police Lt. Tim Cougle said that after a store clerk identified Nguyen, the suspect admitted taking the diamond ring from the J.C. Penney Co. jewelry counter and then fleeing.

Cougle said Nguyen had asked a clerk to see the ring, then once he had it in his hands, “he bolted out the door to a waiting car” a little after 5 p.m. Sunday.

Store employees, however, managed to get a good look at the car as well as take down its license plate number as it fled the Auburn Mall onto Center Street. That description was put out to other police agencies, leading to the state police stop in Falmouth.

The diamond wasn’t in Nguyen’s possession when he was stopped, though.

“He said he dropped it while fleeing the store,” Cougle said.

Cougle said Nguyen was driving the getaway car. He said that police questioned a passenger, but were satisfied that person didn’t play a role in the grab and run.

The investigation into the theft is continuing.

Nguyen has been charged with felony theft by unauthorized taking, Cougle said. A jailer said Nguyen has a court date of Aug. 11.