The shocking death of Karen Swift, her husband's trial and the search for answers

On the night of Oct. 29, 2011, the small town of Dyersburg, Tennessee, was alive with Halloween excitement. That spirit turned truly dark after Karen Swift, a 44-year-old mother of four, vanished. Only her car, found abandoned by two hunters on a rural roadside the next morning, and her two smashed cell phones, discovered near a neighbor's house, remained.

Six weeks later, what began as a missing persons case became a murder mystery, as Karen's body was found hidden beneath a tangle of vines by a caretaker near Bledsoe Cemetery in Dyer County. An autopsy determined that she suffered blunt force trauma to the head.

The case went cold, with no arrests made for over a decade, leaving a shadow over Halloween in Dyersburg and haunting the community. On Aug. 8, 2022, the cold case thawed as police announced the arrest of Karen's husband, David Swift. After being indicted by a grand jury, David was charged with first-degree premeditated murder. He pleaded not guilty to the charge.

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

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

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

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, nor would their key evidence involve fingerprint or ballistic testing.

District Attorney Danny Goodman instead painted a portrait of a rocky marriage, as Karen filed for divorce three weeks prior to her disappearance. The two separated in the past, even divorcing in 2000 before remarrying that same year, but the prosecution suggested that this time was more final.

On the morning of Oct. 29, 2011, the eve of the night Karen disappeared, she rebuffed David's reconciliatory offer to get dinner with him later that evening. The State's theory was that rejection was "eat[ing]" at David, as Assistant District Attorney Tim Boxx put it during the trial, and Boxx speculated that David began to understand that Karen was truly leaving him, "and this time, it's forever."

Daniel Taylor, David's defense attorney, argued that David's attempts to reconcile with Karen should not be read as indicators that he was feeling rejected, but rather as evidence of his hope for a revitalized relationship.

"Did David think maybe they could work it out again like they did the first time?" Taylor asked during David's trial. "Was he hopeful about that? Yes."

The prosecution also alleged that David sought to control and surveil his wife's movements throughout the later days of their marriage.

In response, the defense worked to convince the jury that David's alleged actions did not exist within a vacuum.

Karen's friends and family alleged that Karen took on something of a new identity in the period before her murder. She became involved with a new circle of friends who often attended parties at The Farms Golf Club in Dyersburg. She was also said to have begun 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. "She was determined to be out there having fun with them instead of staying home with the kids where she belonged … [David] was only getting out to see where his wife was."

Taylor also questioned the prosecution's premise that David was in "control" of his wife. Taylor pointed out that she had access to their joint bank account, and that Karen was able to go wherever she wanted. He also underscored that David frequently checked on Karen, "and it got on her nerves," but there was no violence involved.

David echoed this sentiment in his interview with "20/20."

"I never raised a hand on nobody, now or ever," David said to ABC News' Juju Chang. "And I certainly wouldn't do it to my wife or the mother of my children… It's just not my character."

Ultimately, David's trial ended on June 6, with a not guilty verdict on the charges of first-degree premeditated murder and the lesser included charge of second-degree murder. The jury, however, was unable to reach a verdict on the lesser included offense of voluntary manslaughter -- a deadlock that resulted in a mistrial on that charge.

The jury was blocked from hearing about stalking charges that David faces in Jefferson County, Alabama, related to his ex-wife, Kelly Essman. He met Essman on the dating site Christian Mingle in 2014, three years after Karen's death, and the two married in May 2016.

Essman, who has not publicly shared her story before, spoke with "20/20" in an exclusive interview.

"I look at how easily I talked to [David], and believed everything that he told me," Essman said. "And the sense that I got that he was sincere. Why didn't I see it? How do I trust that I can see through anything else?"

"20/20" obtained footage of what appears to be David at Essman’s residence in the middle of the night after they were already separated.

"I pulled up the feed," Essman told "20/20." "And there 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 not yet entered a plea. His attorney has not responded to a "20/20" request for comment on the case.

Despite the allegations raised against him, David's friends and family said they saw a gentle person.

"David is too kind of a person," Kim Greene said of her friend. "He would not harm anybody."

Ashley Swift also remembered her father's compassionate moments, speaking with "20/20" about a time she saw him help a mother pay for her groceries during the holidays.

"She was putting stuff back as she was checking out," Ashley recalled. "And my dad ended up covering all of it so that her kids could have a good Christmas. Things like that really stand out to me."

On Oct. 15, the Tennessee Court of Appeals denied a motion from David's defense team to dismiss the case involving Karen's killing, setting the stage for a new trial on the charge of voluntary manslaughter.  He has pleaded not guilty to the charge.

When Karen Swift first went missing in 2011, the community of Dyersburg was gripped by a deep hunger for answers -- answers that could offer closure for them and justice for Karen.

After 13 years and one trial, this yearning remains unfulfilled. But Karen's memory -- and the hope of those who cherish it -- still promises to endure.

"Ultimately, I know my family's truth," her daughter Ashley told "20/20." "And I know my mom would want me to continue fighting for her."