THE murder of a law professor has taken a chilling turn after the mother of the convicted killer was arrested on conspiracy charges on Monday.

Donna Adelson, 73, was arrested in Florida on charges of first-degree murder, conspiracy, and solicitation related to the hitman death of Dan Markel, a professor at Florida State University and Adelson’s former son-in-law.

Her arrest comes just one week after her son, dentist Charlie Adelson, was found guilty of conspiring to kill Markel, his former brother-in-law, by hiring a hitman to pull the trigger.

And now, newly released court documents that include transcripts of jail calls between Donna and Charlie suggest that Donna played an integral role in the plot to kill Markel.

“Jail calls after Charles Adelson’s guilty verdict include multiple calls in which Donna Sue Adelson is telling Charles Adelson that she is getting things in order, creating trusts, and making sure her grandchildren are taken care of,” says the affidavit.

“Donna discusses plans for a suicide, but also discusses plans to flee to a non-extradition country.

“Donna Sue Adelson has considerable financial resources to do this.”

The affidavit also says Donna had booked flights from Miami to Dubai, where she’d stay for two days.

The last stop on her itinerary was Vietnam.

She was arrested at Miami International Airport Monday night.

Authorities secretly recorded conversations between Charlie and Donna, showing suspicious behavior.

“Does it involve me or other people?” Charlie asks in one of them, per ABC News.

“Well, probably the both of us,” said Donna.

“You probably have a general idea of what I’m talking about. So let’s just find some time to talk to each other.”

Merkel was found shot in the head inside his car in 2014.

As the police investigated the case, they began looking into Merkel’s ex-wife, Wendi Adelson.

A former boyfriend of Wendi pointed the police towards her brother, Charles.

“[Wendi] told me that Charlie had looked into having Danny killed in the summer of 2013,” he told the police.

“She meant it dead serious. He said it would cost about $15,000.”

Donna appeared in court on Tuesday, wearing an anti-suicide vest.

She was silent during her arraignment as she was ordered to be held without bond.