William Wallace, 39, is facing a maximum prison sentence of 15 years to life for the death of 26-year-old Za'Zell Preston
William Wallace
William Wallace
| Credit: Orange County Jail

A California man is facing a potential maximum prison sentence of 15 years to life for killing his wife and propping her up on Christmas morning for her children to open gifts in front of her body, according to officials.

The Orange County District Attorney's Office announced on Wednesday that William Wallace, 39, has been convicted of second-degree murder in the death of 26-year-old Za'Zell Preston.

He is scheduled to be sentenced on June 4.

An attorney for Wallace could not be immediately reached by PEOPLE for comment.

In a press release, the district attorney's office said Wallace "used blunt force trauma to the head" to render Preston unconscious sometime between Dec. 24 and Dec. 25, 2011.

At the time, Preston's 3-year-old and 8-year-old daughters from a previous relationship were in the family's apartment, as well as her 7-week-old son with Wallace, according to prosecutors.

Officials said Wallace called 911 around 9:30 a.m. on Christmas day to report that Preston was in need of medical attention.

Preston was found unresponsive in her home by Anaheim Police Department officers and was transported to a local hospital, where she was pronounced dead.

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

During Wallace's trial, the prosecution claimed that he placed Preston on the couch with sunglasses on and had her kids open presents in front of her body, according to the Orange County Register.

Prosecutors also alleged that Wallace told their children, "Mommy ... got drunk and ruined Christmas," the Mercury News reported.

According to prosecutors, Wallace had spent time in jail for attacking Preston prior to her death.

RELATED VIDEO: Boyfriend Said N.C. Mom Died After Slipping in Bathtub — But 3 Months Later, He's Charged with Murder

"A young mother finally losing her life after years of violence at the hands of her husband is a heart wrenching tragedy," Orange County District Attorney Todd Spitzer said in a statement on Wednesday. "That heartbreak is only exacerbated by the fact that her children witnessed much of the violence and were forced to celebrate Christmas in the presence of their dead mother. That is not a Christmas memory any child should be forced to have."

"We all have an obligation to speak up against violence of any kind, especially domestic violence where the victims are so fiercely controlled by their abusers," Spitzer continued. "The cycle of domestic violence is a vicious one and I want every victim of domestic violence to know that they are not alone. No one should have to live in fear of violence in their own home."

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.