How a South Florida grandmother became the center of a murder-for-hire saga spanning 11 years

Florida State University law professor Dan Markel's last day alive began like many others.

He dropped off his two young sons at preschool and went to the gym, authorities said. But things took a dark turn.

After pulling into his driveway on the morning of July 18, 2014, Markel was shot in the head multiple timesand rushed to a hospital where he died the nextday, authorities said.

Markel had been having custody issues with his ex-wife Wendi Adelson.

Over the next 11 years,twomembers of Adelson's family, including most recently her mother DonnaAdelson, would be revealedas the center ofa stunning murder-for-hire plot against him that would span several criminal trials.

A new "20/20" episode, "Meddler or Murderer?," airing Friday, Jan. 2, at 9 p.m. ET on ABC and streaming the next day on Disney+ and Hulu, examines the case.

You can also get more behind-the-scenes of each week's episode by listening to "20/20: The After Show" weekly series right on your 20/20 podcast feed on Mondays, hosted by "20/20" co-anchor Deborah Roberts.

Wendi Adelsoncame from a prominent dentistry family in South Florida. Wendi's father, Harvey Adelson, and brother Charlie Adelson, werelead dentists at the practice, called the Adelson Institute, according to authorities.

Wendi married Markel in 2006 after previously connecting on a Jewish dating service. However, a controlling figure emerged in their relationship -- her mother, Donna.

Sarah Katherine Dugan, who prosecuted Donna Adelson, said in court that the family matriarch was very involved in all aspects of Wendi's life and relationship with Markel.

"She was extremely controlling. She hadvery strongopinions about all the decisions inWendiAdelson's life, whether it be about her career, her relationships, or evenpurchasinga home," she said.

Wendi Adelson and Dan Markeleventually moved to Tallahassee, where they both got jobs at Florida State University's law school. However, their marriage deteriorated.

"Our marriage dissolved after the children arrived,as the loneliness of being married to someonethatdidn't view me as an equal crept in," Wendi Adelson said in a 2015 podcast.

The couple went through a bitter divorce, and at the center of both of their lives post-separation was the issue of where their two children would live.

Donna Adelson began a fierce campaign against Markel to relocate the children and Wendi down to South Florida with her, but Markel remained insistent on keeping the kids in Tallahassee, 500 miles away, according to authorities.

Markel became increasingly distrustful of Donna Adelson due to her desire to move thechildren away from him, even filing a motion to prevent her from havingunsupervisedvisitswith thechildren in 2014. However, it would be the last motion he would ever file before he was shot to death.

Some two years after the killing, investigatorsarrested two individuals named Sigfredo Garciaand Luis Rivera in 2016, charging them with first-degree murder. The duo was alleged to be hired hitmen who were paid to take out Markel, per prosecutors.

In exchange for a lesser sentence of second-degree murder and 19 years in prison, Riveragave investigatorsthe name of the woman he claimed hired them tocarry outthe hit on Markel -- Katie Magbanua,the mother of Garcia's childand the ex-girlfriend of Adelson's brother, Charlie.

Police then arrested Magbanua in 2016 and later Charlie Adelson in 2022, charging them with first-degree murder, conspiracy to commit murder, and solicitation to commit murder for Markel's death.

Prosecutors alleged thatDonna and Charlieorchestratedthe hit on Dan Markel due to his custody issues with Wendi, and they used Magbanua, Garciaand Rivera to execute their plot.

Magbanua and Charlie Adelson both pleaded not guilty but were ultimately convicted of all charges in 2022 and 2023, respectively,and sentenced to life in prison with an additional 60 years for their conspiracy and solicitation convictions.

Garcia was also convicted of first-degree murderandconspiracy to commit murder and sentenced to life in prison in 2019.He had pleaded not guilty.

After Charlie's conviction,investigatorslearned that Donna Adelson was planning toleavethe country with aone-way ticket to Vietnam -- a country that has no extradition agreement with the U.S.

Policearrested her at the Miami International Airport in 2023, also charging her with first-degree murder, conspiracy to commit murder, and solicitation to commit murder in Dan Markel's killing.

Donna Adelson pleaded not guilty, with her defenseclaimingthat she was not involved in the murder plot.

Adelson, 75, was convicted of all counts against her in 2025 and sentenced to life in prisonwith anextra30 years for the solicitation and conspiracy charges to be served consecutively.

"Never in a million years would I have wanted Danny to be harmed or killed, nor could I ever do something that would leave these two small boys to grow up without him," she said at her sentencing.

In an exclusive new interview with "20/20," EvanHigginbotham, a juror at Donna Adelson's trial, spoke out.

"The prosecution hada long listof evidence," he said. "I think itwas how they presented that evidence in the trial that laid out everything to finally land me a guilty verdict at the end of it."

Dan Markel's mother, Ruth Markel, told "20/20" that she was most proud of her son for being a good dad.

"Danny was a greatfather," she said. "With all his accomplishments, to meI'mthe proudest of him as a father."

Donna and Charlie Adelson have filed appeals for their convictions. Magbanua and Garcia's appeals were both denied in 2025.