Mother-in-law is arrested while trying to flee the country over murder-for-hire plot to kill her daughter's husband amid bitter custody battle - a week after her dentist son was found guilty at trial of hiring the hitman

A Florida mother-in-law has been arrested while trying to feel the country, a week after her son was convicted of hiring a hitman to murder her son-in-law.

Donna Adelson, 73, was seized alongside her husband at Miami-Dade Airport after investigators learned she had a one-way ticket to Vietnam which has no extradition treaty with the US.

‘It was going to be complicated and really difficult trying to bring them back, depending on where they ended up in the world,’ said Leon County State Attorney Jack Campbell.

‘The arrest was not just based on the flight, but that played a part in the timing.’

Son Charlie was convicted last week over the 2014 murder of law professor Daniel Markel who had won a court battle to stop Adelson’s daughter Wendi moving nearer to Adelson’s Miami home with their two children.

Markel was shot dead in his garage and the Adelsons immediately became suspects after Wendi Adelson told detectives that the killing of her ex-husband could have been arranged on her behalf, saying her parents were ‘very angry at Markel’.

The court heard that Donna Adelson ‘hated’ Markel and was ‘desperate to find a way’ to overcome his determination to stop his two sons moving to South Florida.

Markel had asked a judge to prevent her from having unsupervised contact with her grandkids and prosecutors uncovered a July 2013 email in which she reacted to the court ruling.

‘It’s time to take control of your life and not let Jibbers think he’s just ‘won’ anything by having you remain in Tallahassee, eight hours away from the only family you have, and lose out on what will be a job that will afford you and your children advantages that they will never otherwise be able to enjoy,’ she told her daughter.

‘Let’s show this **** what will make him absolutely miserable.

‘You know his weak points; money, religion, control.’

Authorities say the Adelsons offered Markel $1 million to let his ex-wife and sons move, but when he refused Charlie Adelson and other members of the family began plotting his death.

Prosecutors told jurors at trial that Charles Adelson paid to have the prominent professor killed and that he used his girlfriend, Katherine Magbanua, to hire the father of her two children, Sigfredo Garcia, to commit the murder.

They said Garcia enlisted the help of his childhood friend, Luis Rivera.

Magbanua and Garcia were convicted of first-degree murder and Rivera is serving a 19-year sentence after pleading guilty to second-degree murder in exchange for testifying against them.

Markel was shot in the head as he sat in his car outside his Tallahassee home, after taking his kids to daycare and going to the gym.

Investigators were able to track phone records showing numerous calls between Charlie Adelson and Magbanua, her and the killers and Charlie Adelson, and his mother and his sister in the hours before and shortly after the killing, as well as large monetary transactions between the family and Magbanua.

Garcia and Rivera were then linked to a rented Toyota Prius the killers used.

In 2016, an FBI agent, impersonating an extortionist, approached Donna Adelson outside her home and demanded $5,000 to not turn information about the slaying over to investigators. 

The ruse had been concocted in hopes that it would trigger a reaction from the Adelsons.

She contacted her son, telling him they needed to discuss "some paperwork" and that "you probably have a general idea what I'm talking about." They led to several calls and meetings between her and her son.

Charlie Adelson was arrested last year after technicians enhanced a recording made of him and Magbanua inside a Mexican restaurant in 2016 while they were under surveillance discussing the extortion attempt.

In the conversation, Adelson told Magbanua that she would need to meet with the extortionist and agree to a one-time payment.

He also told her he wasn't worried about being arrested, but if he thought police had any evidence proving the family orchestrated the slaying, ‘we would have already gone to the airport’.

During the trial, Wendi took the stand to testify that her family had nothing to do with the 2014 murder of her ex-husband. She denied having any knowledge of the murder-for-hire plot or any involvement herself.

Wendi, who works as an attorney, ended up moving to Miami days after her husband was shot. She was granted limited immunity for her testimony.

Assistant State Attorney Georgia Cappleman asked her: 'In all the years this has been pending, your brother has known who killed your child's father and you didn't know?'

'I did not know,' Wendi Adelson said. 

She testified that she didn't find out about what happened until earlier that day.

Cappleman asked: 'Your family had your ex-husband killed to try to help you, right?' And Wendi responded on the stand: 'No, that’s completely untrue.'

In a police interview in 2014, Wendi Adelson that her brother Charles would joke that he was looking into hiring a hit man, but bought her a TV instead because it was cheaper.

Cappleman asked in court: 'Is that what he said?'

Wendi responded: 'That was the joke that he made in poor taste, yes.'

The TV has always been Wendi's alibi. She has never been accused of any involvement in the murder of her ex-husband.

The mom-of-two was at home the morning of the homicide, waiting for a Best Buy Geek Squad member to come look at her cracked TV.

The victim's parents, Ruth and Phil Markel, and his sister, Shelly Markel, attended the trial and spoke after last week´s verdict.

'This has been a really long and terrible ordeal for all of us,' Shelly Markel said. 'It´s taken a long toll on our lives. And there´s a real sense of relief today.'