Police were initially called to 120th and Aurora just before 11 p.m. to investigate a possible incendiary device.
As officers pulled up to the scene, they spotted a woman punching another woman on the sidewalk, according to police.
They stopped to break up the fight, at which point police say one of the women took off running. An officer jumped out of the patrol car and gave chase. He caught up with the woman in the parking lot of a nearby business.
Police say the woman refused to show her hands, so the officer drew his gun. While drawing the gun, police say the officer accidentally shot the 19-year-old woman in the leg.
The officer immediately called medics and "offered his apologies to the woman," according to police. She was taken to Harborview Medical Center with non life-threatening injuries. The woman was not armed.
When officers ran the woman's name, they learned she was wanted in Snohomish County on several felony warrants. Snohomish county police requested that Seattle police book the woman into jail for the warrants.
The 29-year-old officer who shot the woman has been placed on administrative leave, which is department policy in all officer-involved shootings.
The original call about an incendiary device turned out to be a false report made by a man suffering from mental heath issues, according to police.