A Pennsylvania man was arrested after allegedly leaving a backpack full of Molotov cocktails in a bush outside protests in downtown Pittsburgh, authorities said on Saturday. Matthew Michanowicz, 52, faces federal charges after he was captured on surveillance video placing the military-style backpack at PNC Plaza, according to a complaint by the U.S. District Attorney’s Office for the Western District of Pennsylvania. Authorities said Michanowicz visited the downtown area on a bike to observe the "aftermath" of the riots. They added that during questioning he allegedly admitted to being the person depicted in photographs from the video footage, but denied...