Off duty officer saves the day, but it could have been an armed citizen going to the aid of the officer
When the off duty arrived, the officer under attack was able to defend himself
Mallory had bitten an eyebrow off Anderson, punched him, choked him and slammed his head against the pavement. The fight ended after Jim Weakley, an East Moline detective who happened to be passing by on the bridge, stopped and attempted to get Mallory off Anderson. Weakley couldn't, but Anderson then was able to remove his gun from his holster and shoot Mallory, officials said. Anderson will require plastic surgery.
Note how quick after the taser is fired the suspect attacks