Shannon O'Brien

Police responding to a call about gunfire found the woman around 4 p.m. in the 1700 block of Windward Court, according to a news release. Shannon O'Brien, 28, had been shot at least once. She died at the scene, police said. O'Brien lived in the 4300 block of De Tonty Street, St. Louis, officers said. St. Louis County detectives took the lead on the investigation at the request of the Ferguson Police Department. Shannon O'Brien, 28, was an apparent innocent victim, "simply doing her job when her life was tragically taken," said Vera Clay, a spokeswoman for the St. Louis County Police Department. The ride share driver pulled into the street just before she was shot. Investigators are considering that the shots were intended for her passenger and that the killer or killers had been waiting for the car to arrive, according to a source familiar with the report. Witnesses had reported seeing people with guns on the lot before the shooting. A 16-year-old was charged in juvenile court in connection with the killing, as well as two17-year-olds. A fourth suspect, Noah Johnson, has been arrested as well. Johnson, 18, confessed to police that he was one of the people firing shots from another vehicle. The probable cause statement said an interview with Johnson revealed that the three passengers in the rideshare vehicle were the intended targets due to an ongoing feud.