Extra police remained on duty in Denver for the end of the Juneteenth black emancipation celebration, after one officer was shot in the arm and a bottle-throwing crowd of more than 200 was scattered by tear gas and police dogs in a second night of violence. Juneteenth celebrates the day Texas slaves learned of their freedom in 1865. The observance began in black communities of the South, and blacks carried the tradition with them when they moved north and west. Denver's celebration is held annually in the city's mostly black Five Points area. This year's five-day festival, marred by street riots Friday and Saturday nights after the official festival had closed, ended with a gospel concert.