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“Meddler or Murderer?”: 20/20 Reports on Dan Markel Homicide January 2 2026

by · January 1, 2026

ABC’s 20/20 opens its January 2, 2026 broadcast with a deep dive into one of the most disturbing and protracted murder-for-hire cases in recent American history. Titled Meddler or Murderer?, the two-hour special examines the 2014 killing of Florida State University law professor Dan Markel and the years-long investigation that unraveled a tangled conspiracy. With new courtroom footage, exclusive interviews, and fresh insight into the role of Donna Adelson—the victim’s former mother-in-law—the episode captures the full scope of a murder rooted in custody battles, family loyalty, and calculated violence.

The case drew national attention not only because of Markel’s prominence in academic and legal circles but also for its striking evolution from a mysterious shooting into a saga involving five convictions, a failed airport escape, and questions that still linger over the role of those yet uncharged. Reporter Ryan Smith leads the coverage, offering a comprehensive look at the web of relationships and events that led to Markel’s execution in his driveway—and the fall of an entire family empire.

A Scholar Targeted in Broad Daylight

Dan Markel was a respected scholar of criminal law, known for his writings on retributive justice. A Harvard-educated professor at Florida State University, he had dedicated his life to legal theory and to raising his two sons following a bitter divorce from fellow attorney Wendi Adelson. On July 18, 2014, Markel returned home from errands and was ambushed in his garage, shot twice in the head at close range.

The attack was initially puzzling, but authorities soon focused on the possibility of a targeted hit. Surveillance footage and digital evidence led to the identification of a silver Toyota Prius connected to two men from Miami—Sigfredo Garcia and Luis Rivera. The murder scene, the timing, and the lack of robbery all pointed to a planned execution rather than a random act of violence.

Markel succumbed to his injuries the following day. He was 41. The incident devastated the academic community and drew widespread media coverage, with many initially unaware of the deeper family dynamics behind the crime.

Custody, Control, and a Family Divide

At the heart of the case was an intense custody dispute. After their 2013 divorce, Wendi Adelson was prohibited by court order from moving her children from Tallahassee to Miami, where her family lived. That decision led to years of escalating conflict. In emails introduced at trial, Donna Adelson suggested offering Markel $1 million to allow the relocation, even proposing that she, her daughter, and her son Charles Adelson split the cost.

Frustrated by legal setbacks and resentful of Markel’s parenting restrictions, Donna Adelson became increasingly entangled in the family’s efforts to challenge his role. Prosecutors later argued that this obsession with control—particularly over access to her grandchildren—was the motive behind the murder-for-hire plot. Weeks before the killing, Markel had filed a motion to restrict Donna’s unsupervised time with his sons due to disparaging comments she allegedly made.

The murder cut that legal process short. Days later, Wendi Adelson moved the children to South Florida.

From Miami to Tallahassee: The Hit Men and Their Handler

Sigfredo Garcia and Luis Rivera, both with ties to the Latin Kings gang, were paid to carry out the murder. Rivera later confessed and cooperated with prosecutors, explaining how the men had tracked Markel before ambushing him. In return for his cooperation, Rivera received a 19-year sentence.

Garcia, believed to be the triggerman, was convicted in 2019 and sentenced to life in prison. His connection to the Adelsons came through Katherine Magbanua—his former partner and the mother of his children. She was romantically involved with Charles Adelson at the time of the murder and, according to authorities, served as the intermediary between the Adelson family and the hit men.

Magbanua received thousands of dollars through paychecks from the Adelson family dental practice, even though no work was ever confirmed. She was eventually convicted in a 2022 retrial after a previous hung jury and sentenced to life in prison plus two 30-year sentences for conspiracy and solicitation.

The Arrests of Charles and Donna Adelson

Charles Adelson, a South Florida periodontist and Wendi’s brother, was long suspected of involvement but not arrested until 2022, after authorities enhanced audio from a surveillance recording that captured incriminating dialogue. In a 2023 trial, Magbanua turned on him, testifying that Charles had orchestrated the killing and provided the money for the job.

He was convicted of first-degree murder, conspiracy to commit murder, and solicitation. In December 2023, he was sentenced to life in prison plus 60 years.

Just days after his conviction, Donna Adelson and her husband attempted to flee the country on a one-way flight to Vietnam. She was arrested at Miami International Airport in November 2023. In a recorded jail phone call, she had discussed finding countries without extradition treaties. This attempt to escape became a key piece of evidence in her subsequent trial.

The Trial of Donna Adelson

Donna Adelson’s trial began in August 2025. Prosecutors described her as the “matriarch” who initiated and financed the plot to remove her former son-in-law from the picture. Central to the prosecution’s case was testimony that Donna helped launder the money used to pay the hit men and later tried to cover her tracks through coded conversations and evasive behavior.

Magbanua testified that Donna had provided the cash for the killing and kept her on the payroll afterward to maintain her silence. Financial records showed that Donna personally signed the checks Magbanua received for months after the murder.

Despite her defense team arguing that Donna was merely a “meddler” and not a killer, the jury took only hours to find her guilty. On September 4, 2025, she was convicted of first-degree murder, conspiracy to commit murder, and solicitation. In October, she was sentenced to life in prison.

A Legacy and the Fight for Justice

In the years following Dan Markel’s murder, his parents were cut off from contact with their grandsons, prompting them to advocate for legislative change. Their campaign helped pass the “Markel Act” in Florida in 2022, giving grandparents greater rights to petition for visitation when a parent is murdered and the other parent’s family is implicated.

The case continues to resonate because of the disturbing blend of family betrayal, calculated violence, and a community’s determination to seek justice. With five people convicted, including the victim’s own former in-laws, 20/20’s Meddler or Murderer? provides a definitive account of one of Florida’s most complex and shocking murder cases. The episode underscores the cost of unchecked resentment and the enduring impact of a father’s tragic and unnecessary death.

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Ryan Gill

Ryan is a passionate follower of true crime television programs, reporting on and providing in-depth investigations on mysteries in the criminal world.

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