Police released photographs of the suspect, taken from video surveillance at the AT&T Wireless Store at 594 Walt Whitman Rd.
At about 3:20 a.m. on June 3, the man broke into the store and took an assortment of cellphone mobile devices worth $4,000 from a basement storage area, police said.
The suspect then left in an unknown direction.
Anyone with information is asked to call Crime Stoppers at 800-220-8477. All calls will be kept confidential.