TULSA, Oklahoma - At least seven Dollar General stores in Tulsa have been robbed since November. 

Investigators do not believe they are all connected.

A store at 4th and Lewis was targeted Monday night with the suspect getting away with an unknown amount of cash from the store and one of the customers.

"I said there's a gun, get out," said Rob Detrick. 

Detrick was visibly shaken after an armed robbery while he was shopping at the Dollar General at 4th and Lewis.

"He asked her for the money and I ran like a bat out of heck," Detrick said. 

This is just one of many robberies Tulsa police say they are investigating at Dollar general locations all over Tulsa.

"It would definitely be jumping the gun, no pun intended, to say that we've got a serial robber out there um but there's clearly a problem going on with these dollar stores," said TPD Sgt. Brandon Watkins.

Watkins is head of the robbery division and says most of the incidents at these locations have been very different.

Like one back in November where police say a woman used a taser to steal some items after she was asked to leave a store for being disruptive.

In another case, police say the suspect used a gun and dressed in all black.

Detectives tell us the gun used in last night's robbery was a sawed-off shotgun.

"He may have done two, not quite a serial guy yet because of these seven, we've got wildly divergent suspect descriptions," Watkins said. 

Whether some of these are connected or not, investigators aren't ready to say, but they do say whether someone holds up one store, or a dozen, they want to put them behind bars.

And that's where they say they need to public to speak up.

"They know these guys out there and these guys brag to their significant others and there's always an angry girlfriend out there who's more than happy to call us," Watkins said. 

If you have any information about any of the Doller General robberies you're asked to call CrimeStoppers at 918-596-cops.