Just after 9 a.m. Thursday, RTD transit police Sgt. Andrew Cross got a call on his radio. There were reports of a man outside the Union Station bus terminal threatening to kill people. “This is a daily occurrence,” Cross said as he and RTD officer Stephen Johnson made their way toward the western end of the Union Station campus, “usually many, many times a day.” The officers caught up to the man near 17th Street and Chestnut Place.