A Palos Township man was sentenced Thursday to natural life for the brutal slayings of his parents.

John Granat Jr., 22, was accused of being the mastermind in the 2011 deaths of John Granat Sr. and his wife, Maria Granat. The couple's skulls were crushed with aluminum bats, and then the dying mother was repeatedly stabbed to death.

Prosecutors alleged Granat Jr., then 17 years old, groomed three friends, showered them with cash gifts and promised more money after his parents were dead. He had become enraged with his parents after they discovered he was growing marijuana plants in his room and grounded him, prosecutors alleged. Granat Jr. remained in the family garage and quietly counted stacks of cash the family kept in the house, money he would use to pay off his friends, prosecutors alleged.

On Thursday, Cook County Assistant State's Attorney Deborah Lawler read a statement in Judge Neil Linehan's Bridgeview courtroom from the dead woman's sister, Kathy Sieczka, according to court records.

“The worst part of it, (Granat Jr.) never showed any remorse or regret,” Lawler said while reading the statement. “How could you be so evil?”

The violent killings on the morning of Sept. 11, 2011, rocked the Palos Township-area community where the family lived.

Granat Jr., according to prosecutors, signaled the start of the killings by using a code word: “concert.”

Granat Jr.'s parents were brutally beaten to death in their bed.

Granat and three of his friends — Christopher Wyma, of Bridgeview; Ehab Qasem, of Hickory Hills; and Mohammed Salahat, 22, of Palos Heights — were charged in the killings.

Salahat, who drove the three others to and from the murder scene, pleaded guilty to murder last year and is serving a 35-year prison sentence. Qasem, who pleaded guilty to one count of first-degree murder in the death of Granat Sr., was sentenced earlier this month to 40 years in prison, and Wyma, who has been found guilty, is scheduled to appear in court Friday morning.

Prosecutors said Wyma and Qasem crept into the Granats' bedroom and beat in their heads and bodies with metal baseball bats. Qasem testified that he then stabbed Maria Granat with a knife that Granat Jr. gave him.

Granat Jr. paid for clothing and shoes for the four of them with $100 bills, while giving them the change “because he does not like change,” according to Qasem's testimony.