Robert Liska

Two men died in a double shooting Thursday after one of them apparently began waving a gun at people in St. Louis Square Park, authorities said. Police found Mario Martinez, 32, dead on a sidewalk in the 7900 block of South Broadway shortly before 5 p.m. Thursday. Martinez was killed by the man who had been waving the gun in the park, police said. After shooting Martinez, the suspect ran into a nearby apartment, where a teenager shot and killed him. Police later said the man who apparently shot Martinez was Robert Liska, 23, of the 300 block of Dammert, Lemay. Martinez lived in the 800 block of Wachtel Avenue in unincorporated south St. Louis County. When officers arrived at the shooting scene, in the city's Patch neighborhood, a large crowd gathered. Police issued an "officer in need of aid" call, summoning backup. No officers were injured at the scene or involved in the shooting, police said. A 39-year-old man who saw Martinez get shot told police about the suspect. The witness said he struggled with the suspect over the gun, trying to intervene and help Martinez. As they fought over the gun, the suspect struck the witness in the eye with the firearm, police said. The suspect then ran into an apartment, where a 19-year-old man told officers he feared for his life and fatally shot the suspect.