Tulsa police say gang members are robbing Tulsa restaurants.
They said the robbers belong to an offshoot of the Hoover Crips and that they've robbed more than 20 restaurants in the past six months.
Detectives said there are about a dozen guys in the ring. They say they always hit a restaurant late at night as they're closing or early in the morning as they're opening, they always break a window to get inside and they always have guns.
Surveillance video captured one of the most violent of the robberies at a Taco Bueno.
Video shows the men attacking a female employee who wasn't fighting back, but who was cowering in the corner, with her hands up to fend off the blows.
Sergeant Brandon Watkins said, "Punched her, kneed her, kicked her, stomped her, just brutal."
They've hit five Taco Buenos, three McDonalds, two Braum’s, two Qdobas, a Church's Chicken, Golden Corral, Popeye’s, Sonic, Taco Mayo, CiCi's, Burger King and a Starbucks.
Police have made a couple of arrests - Quentin Nails faces four counts of armed robbery and Courtney Bell is looking at one - but, police said there is so much evidence in the case, it just takes time to catch them all.
Watkins said, "We have to dig through all that evidence until we literally find the smoking gun."
The case has involved a ton of overtime and is a huge priority because they're afraid it's only a matter of time before one of the gang members kills someone during one of the robberies.
"Just last weekend, in a restaurant robbery, we had an accidental gun discharge, but when you give an idiot a gun bad things happen," Watkins said.
Detectives have some more arrests to make in the robbery ring, but just as they're wrapping up this case, they now say they have a new crew out hitting restaurants as well.