Police in Montgomery County said a man left behind his driver's license after a series of crimes in Maryland. (Montgomery County police)

Leaving behind his driver’s license probably made it easier for police to catch a man who they said stole a Lexus from a parking lot in Rockville that had a high-priced violin inside.

The events leading to his arrest began about 5 p.m. March 1 in the parking lot outside a Barnes& Noble bookstore on Rockville Pike. Police said Michael Gainer Rothenberg, 27, of Bethesda walked up to a woman, pulled out a gun and demanded her keys and bag. He then fled in her 2004 Lexus, they said.

Three days later, authorities said, Rothenberg robbed at gunpoint a clerk at a 7-Eleven store on MacArthur Boulevard in Glen Echo.

And Monday, he robbed a gas station in Howard County and fled the scene in the stolen Lexus, police said. He then tried to carjack a woman in a red Mini Cooper to get away, authorities said.

Detectives in Howard County said they found a telling clue — Rothenberg’s driver’s license, which they said he left in the stolen Lexus. And they said he left a receipt showing that a musical instrument had been sold to a pawnshop.

On Monday, Rothenberg was arrested in Frederick, Md. He faces several charges, including armed carjacking and armed robbery.

NBC 4, which first reported the incident, said the violin inside the stolen Lexus was worth $6,000 and was made in 1891 in France. The victim said she was on her way to a music lesson when she was carjacked.

A Montgomery County police detective said the violin had been sold to a pawnshop for $200.

Police said the victim’s violin has been returned to her.