Nearly a month after a Phoenix man was gunned down in his driveway as he returned home from his job at a group home, detectives are still searching for a serial killer believed to be targeting people of color in the area.Horacio de Jesus Pena is one of five people murdered since April. All the victims — male and female age from 12 to 32 — were fatally wounded outside of their homes, near their cars and on weekend evenings in the working-class neighborhood of Maryvale.NBC News reports that an obvious motive is lacking in all cases, but multiple law enforcement agencies confirmed there is physical evidence tying them together. Pena’s sister says she fears the killer will strike again.”For not one person to have more information is mind-blowing,” she said. “This person is still out there. We need to get them off the street.”Police say the first murder in the pattern occurred on April 1. Diego Verdugo-Sanchez, 21, was visiting his fiancee’s family when he was killed near his vehicle. 32-year-old Pena had just gotten out of his car at his home on June 3 when he was ambushed.One week later, 19-year-old Manuel Castro Garcia was standing outside his home when he was killed. On June 12, the killer opened fire on a women and girl listening to music outside a home. 31-year-old Angela Linner and 12-year-old Maleah Russell was killed.