Updated

California prosecutors said Thursday the University of Pennsylvania student who was stabbed to death and buried in a shallow grave in January may have been killed because of homophobia.

Orange County District Attorney Tony Rackauckas said prosecutors added a hate crime sentencing enhancement to the murder charges brought against 21-year-old Samuel Woodward.

Woodward was charged in the death of 19-year-old Blaze Bernstein after investigators said he was the last person to see the pre-med student alive. They said Bernstein was stabbed at least 20 times.

Woodward is said to have picked up Bernstein from his parent’s home in Lake Forest on January 2, and the pair went to the park where the body eventually was found. The two had known each other from attending the same high school.

After Bernstein’s body was found, investigators reviewed Woodward’s cellphone, laptop and social media and found hateful materials against a range of groups, and substantial evidence that Bernstein was killed because of homophobia, Rackauckas said.

Rackauckas declined to specify what materials were found in Woodward’s accounts, but he said they were racist, anti-Semitic, misogynistic and homophobic.

“There’s a lot there that just spews hatred towards a lot of different groups of people, basically every protected group,” Rackauckas said. “So it’s hatred of many different groups of people. But the evidence of the motivation for this particular killing is we can show evidence that he killed him at least substantially, because he was gay.”

Investigators said early in that Woodward told them Bernstein kissed him on the lips, and he pushed Bernstein away. They said in an affidavit that Woodward clenched his jaw and fists as he recounted the events.

Woodward faces a maximum potential sentence of life without parole. He previously faced a maximum sentence of 26 years to life in prison if he were convicted. Under California law, prosecutors can seek the death penalty when a victim is killed because of race, religion or nationality, but not sexual orientation.

He is being held on $5 million bail, and is scheduled for a preliminary hearing on Aug. 22.

The Associated Press contributed to this report.