Professor's Ex-Boyfriend Says Her Brother Discussed Killing Ex-Husband

In a Tallahassee police video obtained by ABC News, the former boyfriend of a Florida State University law professor claims she told him that her brother had talked openly about looking into killing her ex-husband, Dan Markel.

Jeffrey Lacasse and Wendi Adelson had dated for nine months until just before Markel's death. Markel, who was also an FSU law professor, was shot twice in the head on July 18, 2014, as he pulled his car into the garage of his Tallahassee home and died hours later in a local hospital.

Both Lacasse and Wendi Adelson told Tallahassee police that her brother Charlie Adelson talked about hiring a hit man to kill Markel. Adelson told police her brother was joking when he said to her he "looked into hiring a hit man, but decided to buy you a TV instead," and that she didn't take it seriously. But Lacasse told police he took Charlie Adelson's comments to Wendi very differently.

"She [Wendi Adelson] told me that Charlie had looked into having Danny killed in the summer of 2013," Lacasse told an investigator during a 2015 videotaped interview.

"She meant it, dead serious," Lacasse continued. "I would joke around, saying I'd like to kill Danny Markel. ... That is different. She said it in a dead serious, chilling, uncomfortable way. ... In the moment, my stomach flipped. I was like, 'Whoa.'"

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Markel and Wendi Adelson had been through a bitter divorce that was finalized in 2013. Prior to the settlement, Markel had successfully fought her attempt to move with their two young sons to South Florida for a new job and to be closer to her family.

"He [Charlie] said it would cost about $15,000," Lacasse said during the police interview. "It seems cheap to me but you would know better than I."

Lacasse also told police Wendi Adelson said she wanted to take a break from their relationship just days before Markel's murder.

ABC News obtained a copy of videotaped police interviews with Lacasse after a public records request.

Earlier this year, Tallahassee police arrested Sigfredo Garcia and Luis Rivera, two South Florida men with criminal histories, and charged them in Markel's killing. Both have entered not guilty pleas. They are scheduled for separate trials later this year.

No one in the Adelson family has been charged in connection with Markel's killing. Adelson's parents and her brother, Charlie, run a successful dentistry practice in Broward County.

In a probable cause affidavit, police allege that Garcia and Rivera were "enlisted to commit this egregious act" and that police believe the motive for the killing "stemmed from the desperate desire of the Adelson family to relocate Wendi and the children to South Florida, along with the pending court hearing that might have impacted their access to the grandchildren."

After Wendi Adelson's request to take her children out of Tallahassee was denied by the court, she and Markel continued to spar over financial issues and his contention that she had not been abiding by the terms of their parenting agreements. In the months just prior to his slaying, Markel alleged that Wendi Adelson's mother Donna Adelson was making disparaging remarks about him in front of his sons.

His motion seeking to limit his mother-in-law's unsupervised interaction with the children was pending before the court at the time of his death.

Court documents made public in June linked Garcia to Charlie Adelson through Katherine Magbanua, who was Charlie Adelson's former girlfriend and the mother of Garcia's two children. The arrest affidavit alleges that Charlie Adelson "reportedly did not like Markel and did not get along with him."

Police say they have documents that reveal Magbanua "made cash deposits totaling approximately $15,000" into a bank account, and after Markel's death, police say she started receiving checks from the Adelsons' business, signed by Donna Adelson.

"There certainly is some cash that appears to be flowing to them after the homicide," Chief Assistant State Attorney Georgia Cappleman told "20/20."

At the time, police charged the alleged hit men Garcia and Rivera, they also recommended first-degree murder charges against Charlie Adelson and Magbanua, but prosecutors have so far declined to pursue those charges.

"I don't have evidence to charge the Adelsons," Cappleman said. "I can't... accuse them of murder without that evidence."

Wendi Adelson's attorney John Lauro declined to comment for this report. Charlie Adelson's attorney David Oscar Markus told ABC News in a statement:

"Mr. [State Attorney William] Meggs has spent the past 40 years as a prosecutor, with 30 years as State Attorney, and before that was a decorated police officer. He is one of the most experienced State Attorneys in the nation and he knows probable cause when he sees it. We are thankful that he faithfully and honorably fulfilled his duties and did not approve this document, which amounted to no more than simple speculation after a truly exhaustive investigation."

ABC News' Lauren Pearle contributed to this report