In the hours after 10 young people were shot downtown, police are focusing their investigation on the fifth floor of a Washington Avenue building, which despite being an office space, had a group of youths partying in it at 1 a.m. on a Sunday. St. Louis Metropolitan Police Chief Robert Tracy said at a press conference today 17-year-old Makao Moore was killed and nine others aged 15 to 19 were injured by gunfire this morning around 1 a.m. in the building near the intersection of North 14th Street and Washington Avenue.