SPOKANE, Wash. -

The Spokane Police Department executed three simultaneous warrants Monday at three South Hill locations as part of its ongoing investigation of the robbery of a South Hill Little Caesar's franchise.

Major Crimes detectives enlisted the help of the SWAT team to execute the warrants at 30th and Fiske, 9th and Perry and 37th and South Alder Court looking for suspects and evidence in a series of armed robberies back in late May.

One of the robberies was at the Little Caesar's at 29th and Regal on May 26, which detectives think might have been an inside job made possible by an employee who worked at the franchise and may have intentionally set up her own colleagues with an armed robbery.

A trio of young men waited until closing time to make their move, rushing in through the back door of Little Caesar's and threatening the employees with handguns.

At least initially, detectives thought their suspects were just randomly picking late night fast food joints, but then learned a Little Caesar's employee was hanging out with previous offenders who live in the area.

Detective believe that young woman went outside, under the guise of taking a smoke break, but left the backdoor unlocked so her accomplices could get in, rob the franchise and get away.

These latest robberies are especially dangerous for the restaurant's late night staff.

"Demanding that people get to the ground, pointing weapons at people, and that level of aggressiveness or violence can definitely lead to something worse than a robbery," Spokane Police Major Crimes Lieutenant Mark Griffiths said.

Detectives think the same people who robbed Little Caesar's also robbed the Subway franchise a block east on 29th Avenue.

No suspects were arrested Monday but evidence collected during the three warrant executions shows that investigators are on the right track to finding the suspects.