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

The 44-year-old Tennessee mother of four was found dead in October 2011.

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 all the charges.

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 he speculated that David began to understand that Karen was truly leaving him, "and this time, it's forever."

The prosecution also alleged that David sought to control and surveil his wife's movements throughout the later days of their marriage, drawing upon the recollections of numerous witnesses. A neighbor of Karen's friend testified that she once looked outside her home and allegedly discovered David in her yard while Karen was visiting. She claimed that when she questioned him, he told her that he was trying to listen and look through her fence to see what was happening inside.

In response to these claims, the defense worked to convince the jury that these alleged actions, which the prosecution depicted as signs of "controlling" behavior, did not exist within a vacuum.

According to her family and friends, Karen allegedly 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."

Daniel Taylor, David's defense attorney, also questioned the prosecution's premise that he was in "control" of his wife. Taylor pointed out that she had access to their joint bank account, and that Karen Swift 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 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.

There is also much about David's background that did not make it into the trial.

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.

"Did he stalk [Karen]? Did he harass her? Did he do all of that?" Essman told "20/20." "All I know for sure is the stalking and the harassment that he did to me, for sure, I have those facts."

Essman shared surveillance footage with "20/20" of what appears to be David at her 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 likely new trial on the charge of voluntary manslaughter.

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 largely 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."