A man carrying beer approached the register at Big B Liquors in Bryans Road, but he had no intention of paying for it.

When it came time to ring up the sale, authorities say, the customer turned criminal. They say he pointed a gun at the clerk and demanded money from the cash and lottery registers. Then he fled.

After the robbery April 4 at 7099 Indian Head Hwy., security cameras caught him leaving the store.

Charles County Sheriff's Office investigators believe the unidentified man committed two other armed robberies at area supermarkets.

Deputies said the man robbed a Safeway at 3129 Marshall Hall Rd. in Bryans Road on April 20 and the Giant at 4119 Branch Ave. in Marlow Heights on May 5.

In each case, the man, about 5 feet 10 inches and 200 to 250 pounds, waited for the clerk to open the register, drew his gun and then fled with the money, deputies said.

Kristen Adkins, spokeswoman for the sheriff's office, said the nature of the robberies suggested their connection -- "the fact that the suspect goes into a store to purchase something and when he goes to make a purchase brandishes a gun."

Authorities have released two surveillance photos of the man, which are posted at www.ccso.us.

Authorities ask that anyone with information contact Charles County Crime Solvers at 866-411-TIPS.