He's in and out of cell phone stores in less than two minutes. But when he leaves, he makes off with hundreds of dollars worth of phones and cash, according to Gwinnett County police.

Now investigators hope surveillance camera images can help identify the man suspected in seven similar robberies since late May. In some of the cases, a second person is also believed to be involved, Cpl. Jake Smith with Gwinnett police said Wednesday.

The suspect shown in pictures during the robberies, six of which have taken place in unincorporated Norcross and one near Snellville, pulls a handgun from his waistband and orders employees into a back bathroom or closet, Smith said. The man tells the employees not to come out until he has left the store, usually within seconds, according to police.

The robberies began May 26, with the most recent on July 24, police said. And investigators believe about $3,500 in cash and 26 phones have been swiped, Smith told the AJC.

Anyone with information on the suspect or the robberies is asked to contact detectives at 770-513-5300 or Crime Stoppers at (404) 557-TIPS, or visit www.crimestoppersatlanta.org.