WHITE PLAINS, N.Y. (CBSMiami/AP) — Narcy Novack, the South Florida woman convicted of orchestrating the killings of her millionaire husband and his mother, should spend the rest of her life in prison, according to federal prosecutors.

They’ll also seek a life sentence for her brother, who was found guilty with Narcy in the 2009 beating deaths.

READ MORE: FIU President Mark Rosenberg Resigns, Cites Health Issues

“They are evil; they are dangerous; they are remorseless; and they are relentless,” Assistant U.S. Attorney Elliott Jacobson wrote in a sentencing memo to Judge Kenneth Karas.

Narcy Novack and Cristobal Veliz are to be sentenced Dec. 17. They were convicted in June of orchestrating the 2009 killings of Novack’s husband, Ben Novack Jr., and his 86-year-old mother, Bernice Novack.

Ben Novack was the son of the man who built the Fontainebleau hotel in Miami Beach, a celebrity hangout in the 1950s and ’60s that appeared in the movies “Scarface” and “Goldfinger.”

The government said Novack suspected her husband would leave her and wanted to ensure she would inherit the family estate. The sentencing memo says her motives were “hatred, greed and vengeance.”

The fatal beatings, carried out by hit men, were especially brutal, with specific directions from Novack and Veliz, according to testimony.

READ MORE: Armed Robbery In Medley Leads Investigators To Human Trafficking Arrests

Bernice Novack was repeatedly bludgeoned in the teeth and head with a plumber’s wrench at her Fort Lauderdale home. Two months later, Ben Novack was pummeled with barbells and had his eyes sliced with a utility knife in his hotel room in Rye Brook, N.Y.

The killings “involved particularly cruel, sadistic and gratuitous savagery seldom seen in the annals of crime,” Jacobson wrote. He said Novack and Veliz “engaged in the very worst criminal conduct imaginable.”

In addition to the murder charge, the defendants were convicted of domestic violence, stalking, money laundering and witness tampering.

The prosecution also asked the judge to fine Novack as much as $250,000 for each of the 12 counts on which she was convicted.

Novack’s lawyer, Howard Tanner, said he would not respond to the memo until later this week. A call to Veliz’s attorney, Michael Keesee, was not immediately returned.

MORE NEWS: Heat's Late Game Rally Not Enough As Hawks Pull Away 110-108

(TM and © Copyright 2012 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2012 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)