MIAMI: After spending the day combing gay bars and hotels in South Beach for suspected serial killer Andrew Cunanan , the FBI is keeping mum about further developments in its investigation of the slaying of Italian fashion designer Gianni Versace. The agency targeted Cunanan after discovering a red Chevrolet pickup truck authorities believe he stole after allegedly killing a New Jersey cemetery caretaker in May. The vehicle was found Tuesday along a crowded beach front strip a few blocks away from the spot where Versace was shot twice in the head at point blank range. The FBI also reported that Cunanan, a 27-year-old gay prostitute suspected of killing his former gay lover and three other men, had been spotted in West Palm Beach area as early as three weeks ago. While Cunanan is the FBI's lead suspect, agency officials say they are not sure if he was sexually involved with Versace, reports TIME's Miami bureau chief Tammerlin Drummond. "Cunanan is known as a high-class prostitute, but it's not clear whether he knew all of his victims. Right now the FBI isn't saying whether Versace -- who was openly gay -- had any kind of relationship with him."