CHARLOTTE, N.C. -- The Charlotte Mecklenburg Police Department is on the hunt for a serial armed robber.

Police say the man has now targeted six businesses in just three weeks, including a Starbucks on Providence Road. His latest crime happened on Monday afternoon at Carriage Cleaners on Colony Road.

Police have released surveillance photos of the suspect in hopes someone will identify him. Investigators say he acted suspiciously before some of the crimes, and now they want you to be able to spot the behavior and report it immediately.

RELATED: New photos released of suspect linked to 6 armed robberies

Police say the serial armed robber has been known to pace back and forth outside a store before targeting it. They also said he’s been seen wearing sunglasses in the evening.

“We need more to build a case and stop him, frankly before he hits again,” says Sergeant Brian Scharf with CMPD.

The crimes have happened in different parts of town and at different times. The businesses targeted range from a Dairy Queen and Smoothie King on Prosperity Church Road to the Starbucks on Providence Road.

“We use Carriage Cleaners a couple times a month, and I’m distressed to hear that,” said Barbara Jones.

“Especially this time of year, I think a lot of people get desperate,” another shopper told NBC Charlotte.

Police say the suspect has acted nonchalantly while committing the armed robberies.

“In fact, in one of the robberies he did go in and several of the customers didn’t even know it occurred,” said Scharf.

However, CMPD says there have been warning signs. On Thursday, Sgt. Scharf described what witnesses told police about the suspect after the fact.

“‘I saw somebody walking outside at 6:30 at night and he had on sunglasses’, those are the type of things if you see something suspicious we need you to call the police,” said Scharf.

“It’s really scary, I hope they catch him,” said a shopper.

Police say they’re confident the suspect’s luck will run out.

“We’re going to catch him, as far as skill level or smarts I don’t think he’s got either-or,” Scharf said.

Police believe the suspect is acting alone. They say if you have any information about the case call Crime Stoppers at 704-334-1600.