A Southern California man was sentenced to 15 years to life in prison on Friday for murdering his wife on Christmas Eve and then posing her cold body on a couch in front of her two young children as they opened Christmas gifts the next morning.

William Wallace, who was convicted in April of second-degree murder for the 2011 killing of 26-year-old Zazell Preston, was silent throughout his sentencing hearing.

But Preston’s mother, Saidell Preston, offered a gut-wrenching account of the damage Wallace caused to the family.

“He beat and tortured my daughter and at the same time mentally assassinated her children,” Preston told the court, according to the Orange County Register. “He showed her no mercy. Let’s show him no mercy.”

Preston is currently raising her two granddaughters, who were 3 and 8 years old at the time of the murder. During the trial, the eldest daughter described Wallace asking her to help him remove shards of glass from her mother’s body after he’d thrown her into a glass table. She said her mother was cold as Wallace carried her into the bedroom that night.

“After she hit the toilet, and I think she was passed away, he just took her to the bedroom and put her down to sleep while she was deceased,” Preston’s daughter testified. “That is what I remember, because she was cold.”

The next morning, he posed his dead wife on the couch, put sunglasses on her, and vilified her to her two children, prosecutors said.

“Mommy ruined Christmas, she got drunk and ruined Christmas,” he told the two girls as they tried to open gifts near their mother’s dead body.

“I remember trying to touch my mom and she was just rock hard, cold and I said, ‘Mommy,’ and she didn’t respond,” one daughter said during the trial.

Prosecutors said Preston suffered repeated blows to the head in the fatal beating.

Wallace began “beating her in the head, that’s the kill zone,” Orange County Senior Deputy District Attorney Heather Brown said in her closing arguments. “That’s why she’s dead. He hit her in the head over and over... all the injuries to her head killed her.”

Brown described the holiday as a “night of terror” for Preston and said the family’s apartment “looked like a scene from The Shining” when police arrived.

Zazell Preston had been studying to become a domestic violence counselor at the time she was murdered. Several of her family members testified during the trial that Wallace had repeatedly subjected her to savage beatings and had threatened her life numerous times.

Lori Galloway, the executive director of a local refuge for abused women and children, said in a statement to the court on Friday that Preston had been trying to leave Wallace.

“She desperately tried but was savagely beaten and murdered before she could,” Galloway said.

Wallace, who has been behind bars since he was arrested on Christmas Day in 2011, will reportedly get credit for time already served.

In addition to her two daughters, Preston also left behind a 7-week-old son, who was in the Anaheim home at the time of her murder.

“William Wallace robbed us of her knowledge, wisdom and understanding,” Saidell Preston said during his sentencing. “Za’Zell was an amazing and talented young woman, until [he] came along and took her from us forever.”