(Seattle, WA)  --  Police are warning parents of Halloween trick-or-treaters in Washington to watch out for marijuana-infused treats.  Since sales of recreational pot began in the state, cannabis-infused edibles have been popular.  Police say that if treats, especially cookies or other baked goods, aren't professionally packaged in a factory, that's reason to believe something might be wrong.  Authorities say they haven't received reports of kids accidentally getting pot-laced edibles in Washington, but they want parents to be prepared.