Marlene Warren was finishing breakfast with her son and his friends on May 26, 1990, when a white Chrysler LeBaron pulled into the driveway of her home outside West Palm Beach, Florida.
Someone dressed as a clown emerged from the car carrying two balloons and a flower arrangement, authorities said.
When Warren answered the door, the clown handed her the gifts, according to detective Paige McCann of the Palm Beach County Sheriff’s Office. “Warren said something like, ‘How nice,'” McCann said.
The clown then pulled out a gun, shot Warren in the face, walked back to the car and calmly drove away.
Warren died two days later in a hospital.
At the time, investigators said they had identified a suspect but didn't have enough evidence for a conviction. No arrests had been made in the brazen killing -- until Tuesday.
Sheila Keen, who married the slain woman's husband 12 years after the killing, was taken into custody in Abingdon, Virginia, a mountain town more than 800 miles from the site of the slaying.
Keen, 54, has been charged with first-degree murder in Warren's killing 27 years ago. No plea has been entered yet.
She waived extradition back to Florida, and prosecutors will announce whether they will seek the death penalty once she returns to the state, according to Palm Beach County State Attorney David Aronberg .
CNN has reached out to the suspect's lawyer for comment.
For years, there were no breaks in the case until 2014, when the Palm Beach County Sheriff's Office cold case unit reopened the investigation.
Authorities tracked down witnesses, re-interviewed them and examined evidence using DNA technology not available in 1990, according to McCann.
Detectives also discovered the suspect married Michael Warren, the widower of the victim, in 2002. When detectives first looked into the killing, they heard rumors the suspect was having an affair with Michael Warren, McCann said.
At the time, Michael Warren and Keen denied having an affair.
They were together in a car when she was arrested Tuesday, said Fred Newman, the sheriff in Washington County, Virginia.
Michael Warren has not been charged, but the investigation is not over, Florida investigators said.
The Miami Herald reported that the suspect used to run a car repossession business in South Florida. Michael Warren was one of her customers, and operated his own used-car and rental-car businesses, the newspaper said.
Before her arrest, the couple lived around Abingdon and nearby Kingsport, Tennessee, for several years, authorities said.
Palm Beach County investigators declined to share additional details about the case, saying the investigation is ongoing.
But they said they determined the balloons and flowers were purchased the day of the killing at a grocery store near the suspect's residence.
Investigators also discovered that the suspect and Michael Warren had possession of the car before the killing, McCann said. That car was a rental from another company that customers mistakenly returned to Michael Warren's car lot, she said.
Palm Beach County Sheriff Rick Bradshaw said advancements in DNA evidence helped seal the case. In 1990, the evidence was just not strong enough to secure a conviction, he said.
Investigators would not go into specifics about what DNA evidence strengthened the case. But in 2000, investigators said they hoped orange fibers and brown hair found in the car would help them find the killer, according to the Miami Herald.
"Remember the days when we had the cell phones ... that looked like a brick, and now we got smartphones that you can do everything on," he said. "That's the difference between the technology back when this happened and today. It's exponentially so much better to assist us in making sure we have the right person."
The victim's mother, Shirley Twing, said she always believed an arrest would be made in her daughter's killing.
"Kind of choked me up a bit. ... Sometimes I feel like crying when I'm talking about it," Twing told CNN affiliate WPTV.
"I had faith ... never gave up, you know?" she said, thanking investigators for their work.
Joseph Ahrens, the victim's son, told CNN he was grateful of the progress in the cold case.
"I think they took so long to make an arrest because they just wanted to be sure they had the right person," he said.