Philadelphia police say a man accused of killing two gay men because of their sexual orientation remains at large.Authorities this week called for the public’s assistance in apprehending Jahylin Melchur, 21, who is suspected in two homicides and another shooting. Police say Melchur is wanted in connection with the fatal shootings of Martin Higgins, 45, who was shot and killed on West Hunting Park Avenue on June 20, and Sharef Holman, 29, who was killed on the same street on June 26. Melchur is also wanted in connection with the shooting of a 55-year-old man on May 29 on Lycoming Street. That man survived.Law enforcement sources told NBC affiliate NBC10 Philadelphia that they believe Melchur targeted his victims because they were gay. Authorities told the station both Higgins and Holman were shot in the back. Higgins was shot around 10 p.m. June 20 at a baseball field and died at the scene. Holman was found a few blocks away around 11 p.m. June 26 and was transported to a hospital, where he died at 11:29 p.m.The man who survived was shot around 10 p.m. May 29 and was found lying next to his car with gunshot wounds to his elbow and side, Philadelphia Deputy Police Commissioner Frank Vanore told the NBC station.Vanore told ABC affiliate 6 Action News that authorities believe Melchur was spotted on surveillance footage using the Southeastern Pennsylvania Transportation Authority’s Broad Street Line.“We know this individual seems to be preying on people in that area. So, if someone does ride SEPTA at those times, around 10 p.m., they know this individual, know where this individual may live or hang around - we'd like to know," Vanore said.Police released images believed to be on Melchur wearing a red-and-black hoodie and a grey hoodie under a black jacket.Police have urged anyone with information to call the Philadelphia Police Department Homicide Unit at (215) 686-3334. Anonymous tips can also be made by calling (215) 686-TIPS (8477).The ongoing investigation is t