The girl had arranged to meet "an acquaintance to exchange personal property" in the 900 block of Lititz Pike on April 14, at 7:20 p.m., Northern Lancaster County Regional police say.
The girl got into their car and "another passenger brandished a handgun and (forcibly) stole the victim's cell phone," police say.
She was able to escape unharmed; the driver and suspect fled the scene, but on Monday, May 4, the NLCRPD released the name of the suspect.
Jakobi William Frazier, 18, of Cecilton, Maryland, is wanted on charges of felony robbery and possession of a firearm having been used as an instrument of a crime, according to the police.
He is described as being Black, 5 foot 10 inches tall, weighing approximately 130 pounds, with brown hair, and brown eyes.
Anyone with information on Frazier's whereabouts is asked to contact the NLCRPD at 717-733-0965.
Click here to follow Daily Voice Gaithersburg and receive free news updates.