Jacob Mercer

Maryland Heights officers at about 6 p.m. were called to the store, at 12509 Dorsett Road, police said. The officers said they found a man with a gun who then began firing at them. One of those officers returned fire and struck the man, who died at the scene, police said. Jacob Mercer, 23, police said. St. Louis County police are investigating the case. The Maryland Heights police officer who fired shots is 30 years old with two and a half years of experience at the department, plus other experience at a different department. Mercer lived in the first block of Brush Creek Court in St. Peters, police said.