PHILADELPHIA - A deadly discovery has launched a shooting investigation in North Philadelphia Tuesday morning.Police found a body laying in a vacant lot when they were called to the 3000 block of North 16th Street around 2:30 a.m.The 28-year-old, who has not been identified, was bleeding from the head and leg, according to authorities.MORE HEADLINES:Three spent shell casings were also found at the scene.A motive is unknown, and a suspect description has yet to be released..