PORTLAND, Ore.—Some people in a small crowd calling for the abolition of police broke windows as they marched in Portland on Monday night, hours after authorities said that a man who was fatally shot by an officer in a city park last week had an orange-tipped replica gun. The Portland Police Bureau said on Twitter late Monday it had made two arrests for criminal mischief after declaring the assembly of about 80 people in northeast Portland unlawful. Windows were broken at a bank building, a fast-food restaurant, a grocery store, and at a Boys and Girls Club, the department said. The protest followed the police killing Friday of Robert Douglas Delgado, 46, who had reportedly been acting like a cowboy and doing “quick-draws” with what appeared to be a handgun in Lents Park. Delgado’s gun turned out to be a replica with an orange tip, which is typically intended to …