(Portland, OR)  --  Mayor Charlie Hales is calling for a use-of-force investigation of an incident involving a Portland police officer at an anti-Trump demonstration.  KATU-TV reports a video taken during the march shows the officer using a pressure point to subdue an already-handcuffed protester, 24-year-old Kathryn Stevens, during the protest.  Stevens was detained after she attempted to stop police from arresting Portland's Resistance leader, Gregory McKelvey.  Hales says he's asked the Independent Police Review to investigate the use of force.