The mother of a black teenager shot and killed by a white police officer outside Pittsburgh told supporters at a vigil that she was glad to see her son’s life celebrated at a place that meant so much to him. Michelle Kenney, mother of 17-year-old Antwon Rose II, joined scores at the Hawkins Village housing complex in Rankin. People brought red roses, white flowers and candles, and purple ribbons to the basketball court _ which Kenney called “his spot” _ where they sang and prayed.