West Palm Beach - On a May morning in 1990, Marlene Warren answered her front door in an upscale Florida suburb to find a clown in an orange wig, red nose and white face paint, handing her carnations and foil balloons."How pretty!" she exclaimed.The clown then pulled a gun, shot Warren in the face and drove away. She died two days later.Jailed without bailNow, almost three decades later, authorities have made an arrest in the slaying: a woman who, years after the killing, married Warren's husband.Detectives said advances in DNA technology, combined with evidence gathered decades ago, show Sheila Keen Warren, now 54, was the clown.At the time of the shooting, she was an employee of Marlene Warren's husband, Michael, at the family's used car lot. She has been his wife since 2002.She was arrested at the home she shared with him in Abingdon, Virginia and was jailed without bail to await extradition to Florida on first-degree murder charges.Michael Warren, 65, has not been charged, but detectives refused to rule him out as a suspect and said he was interviewed again.Sheriff's Detective Paige McCann, who headed the investigation, and Palm Beach County Sheriff Ric Bradshaw said on Thursday that it had been the new examination of DNA collected in 1990 that allowed them to arrest Sheila Warren, who had been the primary suspect since the shooting. Without it, there might not have been enough evidence to convince a jury, they said."You basically get one shot and if you roll the dice and take that chance and she is found not guilty, you never get that chance again," McCann said. "Sometimes patience is the best".She and Bradshaw would not give any details on the genetic material or where it was found.Repossessed carsWitnesses had told investigators in 1990 that Sheila Warren and Michael Warren were having an affair, though both denied it.Over the years, detectives say, costume shop employees identified Sheila Warren as the woman who had bought a clown costume a few days earlier. And one of the two balloons - a silver one that read, "You're the Greatest" - was sold at only one store, a Publix supermarket near her home. Employees told detectives a woman who looked like Warren had bought the balloons an hour before the shooting.The presumed getaway car was found abandoned with orange, hair-like fibers inside. The white Chrysler convertible had been reported stolen from Michael Warren's car lot a month before the shooting. Sheila Warren and her then-husband repossessed cars for him.Relatives told The Palm Beach Post in 2000 that Marlene Warren, who was 40 when she died, suspected her husband was having an affair and wanted to leave him. But the car lot and other properties were in her name and she feared what might happen if she did.She allegedly told her mother, "If anything happens to me, Mike done it".Michael Warren was convicted in 1994 of grand theft, racketeering and odometer tampering and served almost four years in prison. He and his wife recently sold a popular restaurant in Kingsport, Tennessee, according to the Bristol Herald Courier.