Nearly 11 years after Florida State University law professor Dan Markel was gunned down in his driveway, his former mother-in-law, Donna Sue Adelson, is set to face murder charges on whether she masterminded the killing.

The 75-year-old grandmother is accused of first-degree murder, conspiracy, and solicitation of murder in what prosecutors call a cold-blooded family plot to free her daughter, Wendi Adelson, from a bitter custody battle. She has pleaded not guilty.

Former Palm Beach County State Attorney Dave Aronberg, who was also a friend of Markel, told Fox News Digital the long wait for trial was deliberate.

“The day of reckoning for Donna is here and justice has come slowly, but it is going to arrive,” he said. “Prosecutors had to go step by step, starting with the hitmen, then Katherine Magbanua [Adelson’s former girlfriend], then Charlie Adelson [Markel’s former brother-in-law]. Only then did they have enough to take down Donna.”

Donna Adelson virtually appears in court Jan. 22, 2024, for a case management hearing. Adelson is charged with first-degree murder in the 2014 death of her son-in-law, Dan Markel. (Jeff Burlew/Imagn)

Wendi has not been charged but has been repeatedly named in court filings. She has fought a subpoena to testify at her mother’s trial, arguing it could jeopardize her Fifth Amendment rights. Aronberg expects she will still take the stand, under immunity if called by the prosecution.

“As for Donna, she’ll testify too,” Aronberg said. “She really believes her story. But just like Charlie, she’ll learn the jury isn’t buying it.”

Fox News Digital has reached out to Donna Adelson’s defense team, Jackie Fulford and Joshua Zelman, for comment.