On the night of October 29, 2011, the small town of Dyersburg, Tennessee was filled with Halloween excitement. This spirit turned completely dark after the disappearance of 44-year-old mother of four Karen Swift. All that remained was his car, which was found abandoned on a rural roadside the next morning by two hunters, and two smashed cellphones found near a neighbor’s house.

Six weeks later, what started as a missing person case turned into a murder mystery when Karen’s body was found hidden under a pile of vines by a caretaker near Bledsoe Cemetery in Dyer County. An autopsy determined he suffered blunt force trauma to his head.

The case went cold for more than a decade without any arrests, casting a shadow over Halloween in Dyersburg and haunting the community. On August 8, 2022, the cold case was resolved when police announced the arrest of Karen’s husband, David Swift. David was charged with first-degree premeditated murder after being indicted by a grand jury. He did not accept the accusation.

Watch the “20/20” episode “Her Last Halloween” airing Friday, Nov. 1 at 9 p.m. on ABC and streaming on Hulu starting Nov. 2.

The arrest came as a shock to many people, including David and Karen’s then-20-year-old daughter Ashley.

“You know, I remember trying to figure out why,” Ashley Swift said in a new interview with “20/20.” “Why now? Why is this happening after all these years?”

David’s trial began on May 28, 2024. Community members wondered what evidence would explain his sudden arrest after 11 quiet years.

On the first day of the trial, the prosecution warned the jury that they would not present this as a DNA case and that their key evidence would not include fingerprints or ballistics testing.

District Attorney Danny Goodman instead painted a portrait of a rocky marriage, with Karen filing for divorce three weeks before her disappearance. The pair had separated in the past, even divorcing in 2000 before remarrying the same year, but the prosecution argued this time was more definitive.

On the morning of October 29, 2011, the eve of the night Karen disappeared, he turned down David’s conciliatory offer to have dinner with her that evening. The state’s theory was that rejection was “food”(english)against David, as Deputy District Attorney Tim Boxx testified during the trial, and Boxx speculated that David was beginning to realize that Karen had truly left him, “and this time it’s going to be forever.”

David’s defense attorney, Daniel Taylor, argued that David’s attempts to reconcile with Karen should be read not as indications that he felt rejected, but rather as evidence of a revived hope for a relationship.

“Did David think maybe they could fix the problem again like the first time?” Taylor asked during David’s trial. “Was he hopeful about that? Yes.”

The prosecution also alleged that David attempted to control and monitor his wife’s movements in the later days of their marriage.

In response, the defense attempted to convince the jury that David’s alleged actions did not exist in a vacuum.

Karen’s friends and family claimed that Karen had assumed a new identity in the period before the murder. He met a new circle of friends who frequented parties at The Farms Golf Club in Dyersburg. He was also said to have started drinking and going out more.

“Karen’s behavior changed with this new group,” David’s friend Kim Greene told “20/20” in an exclusive interview. “He was determined to go out and have fun with the kids instead of staying home with them where he belonged… (David) “He was just going out to see where his wife was.”

Taylor also questioned the prosecution’s claim that David was “under the control” of his wife. Taylor stated that he had access to joint bank accounts and that Karen could go wherever she wanted. He also emphasized that David checked on Karen frequently “and it got on her nerves”, but that there was no violence involved.

David echoed this sentiment in an interview with “20/20.”

“I have never raised my hand to anyone, not now or ever,” David told ABC News’ Juju Chang. “And I certainly wouldn’t do that to my wife or the mother of my children… That’s not in my character.”

Ultimately, David’s trial ended on June 6 with a not guilty verdict on first-degree premeditated murder and second-degree murder charges. However, the jury was unable to reach a verdict on the lesser charge of premeditated manslaughter; this was a stalemate that led to a mistrial on this charge.

The jury was prevented from hearing the stalking charges David faces in Jefferson County, Alabama, regarding his ex-wife, Kelly Essman. She met Essman on the Christian Mingle dating site in 2014, three years after Karen’s death, and the two married in May 2016.

Essman, who has not previously shared her story publicly, spoke to “20/20” in an exclusive interview.

“I look at how easily I speak (David)and I believed everything he told me,” Essman said. “And I got the feeling that he was sincere. Why didn’t I see it? How can I trust that I can see through anything else?”

“20/20” obtained footage of David at Essman’s home after he left in the middle of the night.

“I filmed it,” Essman told “20/20.” “And he was in my backyard in the middle of the night… He had to drive 40 minutes one way to get to my house.”

David was charged with felony stalking in Alabama in July 2023 and has yet to enter a plea. His attorney did not respond to a “20/20” request for comment on the case.

Despite the allegations against him, David’s friends and family said they saw a kind person.

“David is such a kind person,” Kim Greene said of her friend. “He wouldn’t hurt anyone.”

Ashley Swift also recalled tender moments from her father; With “20/20,” she described a time when she saw him helping a mother pay for groceries during the holidays.

“He was putting his stuff back when he was checking out,” Ashley recalled. “And in the end my dad covered it all up so his kids could have a good Christmas. Stuff like that really gets my attention.”

On October 15, the Tennessee Court of Appeals rejected David’s defense team’s request to dismiss the case for Karen’s murder, setting the stage for a new trial on the premeditated manslaughter charge. He did not accept the accusation.

When Karen Swift first disappeared in 2011, the Dyersburg community faced a deep hunger for answers; Answers that could put an end to them and bring justice for Karen.

After 13 years and one try, this aspiration was not realized. But Karen’s memory and the hope of those who cared for her remain.

“At the end of the day, I know the truth of my family,” daughter Ashley told “20/20.” “And I know my mom would want me to keep fighting for her.”