The murder has remained unsolved for nearly 30 years.
Here’s a look back at what happened that rainy morning on Memorial Day weekend, May 26, 1990.
Marlene Warren lived in the prosperous Aero Club neighborhood in Wellington, where many of the large homes on one-acre lots have backyard hangars for their owners’ private planes. An airstrip runs through the center of the community.
The steamy season was beginning to settle in across South Florida that Saturday when a clown came to Warren’s door just before 11 a.m.
Answering the door, a smiling Warren accepted the bundle of flowers and balloons the clown held.
“Oh, how pretty,” her son remembered her saying.
They were the last words she would speak.
Wearing an orange wig, red nose and gloves, camouflaged with white paint creating a grotesque happy face, the death-dealing clown raised a pistol and delivered a single shot at point-blank range to Warren’s face.
Her 21-year-old son, Joey Ahrens, in the living room with a group of friends, reached his mother as she collapsed amid a spreading pool of blood.
He recalled seeing the clown’s brown eyes before it climbed into a white Chrysler LeBaron convertible.
Warren, 40, died two days later.
Homicide investigators focused on Warren’s husband, Michael, 38, and Sheila Sheltra Keen, 27, whom Warren had hired to repossess cars for his West Palm Beach used car lot. Acquaintances told police Michael Warren and Keen were having an affair, which they denied.
Over the next few years, investigators compiled reams of circumstantial evidence, but with no fingerprints, eyewitnesses or the kind of sophisticated DNA analysis possible today, they didn’t have enough to bring charges.
Marlene Warren’s killer has never been caught.
Twelve years after the murder, Michael Warren and Sheila Sheltra married in Las Vegas.
Marlene feared her husband, Michael, would kill her.
She told her parents and her son that she wanted to leave him, according to her mother and stepfather, Shirley and Bill Twing, in a Palm Beach Post interview in 2000. Marlene was sure there was another woman.
Leaving would be complicated. The couple’s businesses and real estate properties, worth more than $1 million, were in Marlene’s name.
“They were having problems,” Marlene’s stepfather, Bill Twing, said 17 years ago. “If she would’ve left him, it would’ve cost him dearly.”
Shirley Twing said Marlene told her, “If anything happens to me, Mike done it.”
A few hours after the murder, an anonymous caller told police they should question Michael Warren.
The Twings, Las Vegas residents now in their mid-80s, did not return phone calls for this story.
Police ultimately decided Michael wasn’t the trigger man, although they suspected he was involved. When the clown appeared at Marlene’s door, Michael was on Interstate 95 headed for Calder Race Track.
The focus veered to Keen, a striking young woman with long brown hair and brown eyes, after police in October 1990 said the clown was a woman. Deputies found only one Publix in Palm Beach County that sold the kind of Mylar balloons the clown carried.
“It was at Community and Military Trail,” Sgt. Bill Williams recalled in 2000, the lead detective on the case in 1990. “It was across the street from where the husband’s supposed girlfriend lived.”
The store’s clerk described the buyer as having long brown hair, according to Williams. “This was purchased, let’s say, about a half-hour or 45 minutes before the murder occurred.”
Deputies said salespeople at a Dixie Highway costume shop tentatively identified Sheila Keen as the woman who purchased a clown costume two days before the murder.
Keen’s estranged husband, Richard, told police shortly after the murder that his wife and Michael Warren were having an affair. Neighbors at Keen’s West Palm Beach apartment told police that Michael was there so often they thought he and Keen were married.
Police also linked the stolen Chrysler getaway car to Warren’s A Bargain Auto Rentals. Inside, they found orange fibers and brown hair, but the rudimentary DNA tests of 1990 yielded little.
“We were hoping to get the state attorney to prosecute, but there was always some doubt as to who the trigger person was,” said Williams, commenting 10 years after the crime.
The relationship between Michael Warren and Keen seemed to take a turn a few weeks before the killing, according to records of a police interview.
Sheila and Michael stopped having long lunches together, an employee told police. Warren was putting her off and she “did not appear to like it,” the report read.
Keen was a Glades girl who grew up in LaBelle and Indiantown. In 1987, she married Richard Keen, a 20-years-older former Ku Klux Klan leader nicknamed “Spud,” after waiting for him to finish a Georgia prison sentence for marijuana trafficking. She gave birth to a baby boy a few months later.
“She liked to live rich,” a former boyfriend said of her in 1990. Of Richard Keen, he said, “Money was one of his gods.”
After Richard left prison, the couple lived in a small apartment in a Pahokee trailer park. Several years before a clown gunned down Marlene Warren, Sheila entertained employees’ kids at a Pahokee parts store, wearing a clown costume, said an employee at the time.
Sheila Keen denied to police having a clown suit or shopping at Publix that day. The day of the murder, she told police she was in Lake Worth, Boynton Beach and Riviera Beach looking for cars to repossess.
Keen’s family and friends in Indiantown were stunned that she could be connected to such a crime.
“She’s too sweet a person for this to happen,” her cousin Raymie Sheltra told The Post a few months after the murder.
In 1990, the Keens were running a vehicle repo business when they were hired by Michael Warren.
Investigators’ scrutiny of Michael Warren’s car businesses led to his arrest five months after his wife’s murder on charges of odometer tampering, grand theft and and racketeering.
Warren’s attorney accused prosecutors of railroading his client because they couldn’t muster enough evidence for a homicide charge.
Michael Warren was convicted in August 1992 on 43 felony counts and sentenced to nine years in prison, of which he served three.
Assistant state attorney Allen Geesey, now an assistant in the West Palm Beach office of the state attorney general, called Warren a suspect in his wife’s death in 1992. Earlier this month, he said he couldn’t comment on a murder case gone cold for nearly 30 years.
In the months after the killing, Michael Warren sold the couple’s home and other properties. He quit-claimed some properties to Marlene’s 21-year-old son, Joey Ahrens, who lost them when he couldn’t pay the mortgages.
Since 2008, Ahrens has owned a small construction business in Cedar Falls, Iowa. He didn’t return numerous phone calls from The Post.
After his release from prison, Michael Warren and Sheila Keen seem to have disappeared from Palm Beach County.
Sheila Sheltra (she resumed her maiden name) divorced Richard in 2000, then married Michael Warren in Nevada two years later.
In 2004, Sheila Sheltra Warren bought a home on the Holston River in Abingdon, Virginia, near the Tennessee border valued at nearly $600,000, according to Washington County, Virginia property records.
In 2000, Sgt. Bill Williams, the lead detective on the murder in 1990, looked back at the perplexing case.
“This case was a set of circumstances that pointed in one direction,” said Williams. “Just because you can point the finger doesn’t mean you got enough to convict them.”
A Palm Beach County Sheriff’s Office spokesperson said the department had no new information to release on the case.
Whoever killed Marlene Warren still roams free.
Palm Beach Post researcher Melanie Mena contributed to this story.
STILL SEEKING CLUES
Anyone with information on the 27-year-old “clown murder” of Marlene Warren of Wellington is urged to call Crimestoppers at 1-800-459-TIPS.