Officers responded to an armed robbery in progress late Sunday night at a convenience store in the 1400 block of NW Sammamish Road.
By the time they arrived, the robber, a woman with dark hair, was already gone.
A clerk said the woman walked into the store displaying what looked to be handgun, according to police. The woman approached the clerk and demanded money, but the employee refused and the pair began to scuffle.
At some point in the melee, the clerk was able to disarm the woman.
Undeterred, the robber then pulled a knife on the clerk and once again asked for money. Once again, the clerk disarmed the woman, at which point she gave up and ran away.
The clerk wasn't injured.
Officers, including a K-9 unit, searched the area but were unable to locate the woman.
Police say she stands about 5'5" tall and has a medium build.