PHILADELPHIA — Jakir Waters was driving to his mother’s house to baby-sit his 3-year-old brother one morning in early October 2020. First, though, the 19-year-old stopped on a side street in South Philadelphia to see a friend. Waters, 21, said he was double parked and chatting out the window, when he noticed a car behind him, dark tinted windows concealing who was inside. Unsettled, Waters pulled off. The black sedan followed, staying with him as he serpentined through narrow streets. “I didn’t know who it was. … I thought it was someone out to kill me,” he said. “There’s a lot of stuff going …