This is how the accused killer of the California Ivy league student gets his kicks — by pretending to crush a friend’s skull on a concrete block.

While the teen on the ground with his head propped on the yellow parking barrier was unharmed, the photo reveals a disturbing fascination with violence.

But the chilling snap — posted on the social media app iFunny — pales in comparison to the hate-filled ideology 20-year-old Samuel Woodward allegedly spewed online, The Post has found.

Multiple sources say Woodward created the now-deleted iFunny account under the handle “Saboteur” — and used it to spread white-supremacist and Neo-Nazi screeds.

Indeed, the photo appears to recreate the gruesome “curb stomp” attack depicted in 1998’s “American History X,” in which Edward Norton stars as a neo-Nazi skinhead.

The newly revealed online persona could shed new light on a possible motive in Woodward’s alleged murder of 19-year-old University of Pennsylvania pre-med student Blaze Bernstein, who was found stabbed 20 times in a shallow grave in an Orange County, Calif., park on Jan. 9. Bernstein was Jewish.

Speculation on a motive has so far centered on Woodward’s sworn statement saying he flew into a rage after Bernstein tried to give him an unwanted kiss. In the reported police affidavit, Woodward allegedly said he had wanted to call his former high school classmate “a faggot.”

Police have not ruled out a hate crime.

Saboteur “was one hundred percent a White Nationalist from his comments that I personally saw,” said an iFunny app user who wanted to be identified only as Daniel W.

Saboteur over the years had posted purported photos and videos of himself, and a former teacher and multiple iFunny users confirmed those images were of Woodward.

A disturbing racist, sexually charged caption accompanied one photo Woodward purportedly posted of himself, wearing a commencement gown, and posing with a young female teacher of Indian or Middle Eastern descent.

“I would vigorously bone the living hell out of my English teacher, like holy f- -k. I don’t care if it’s miscegenation [interbreeding], That babe would be pregnant as f- -k year after year, around the clock, acting as a hub of genetic imperialism and giving life to half arab Saboteur-offspring to further my conquest and aims,” it said. The high school would not comment on the twisted boast.

During debates on the phone app, Woodward consistently spouted defenses “of white nationalism and support of Nazi ideas,” said Daniel W.

“Anti-Semitism and homophobia were certainly aspects of his ideology,” said another iFunny user who claimed to be close to Woodward.

The iFunny app is designed for users to upload funny memes, photos and videos to their accounts for other users to comment and re-share.

But sources claim Woodward mostly posted diatribes in the “iPolitics” group.

“Sam was a radical National Socialist. He dedicated his account to radical nationalist movements throughout history and worked towards spreading his ideology,” the source close to Woodward wrote.

Woodward’s posts grew more disturbing over time, according to the source.

He “went from a man interested in right-wing ideology to a much more concerning and dangerous belief system,” the source said, including espousing “white revolution.” Another source said he expressed hate for refugees.

Such an evolution isn’t unusual, according to the Anti-Defamation League.

“Meme culture has been embraced by white supremacists, who are very active online and increasingly seek to employ irony and humor to spread their hateful messages,” said Oren Segal, director of ADL’s Center on Extremism.

Despite Woodward’s rhetoric, he was also regarded as “one of the smartest and most sane nationalists on the app,” the source said.

Woodward drifted away from iFunny in the last year and deleted the “Saboteur” account, the sources said.

On Jan. 12, Woodward was arrested and charged with murder of the baby-faced Bernstein. On Jan. 4, a visibly nervous Woodward was questioned by cops about the missing Bernstein, because the two had communicated by snapchat shortly before the victim’s disappearance two days earlier. Investigators noticed his scratched hands and dirt-filled fingernails, according to court filings, and Woodward claimed it was from a “fight club.” Cops later observed him clean out his car and return to the scene of the crime.

Both Woodward and Bernstein had attended the Orange County School of the Arts in Santa Ana through 10th grade before Woodward transferred to Corona del Mar High School to finish out his junior and senior years.

Bernstein was home on winter break when he left his parent’s house on Jan. 2 without telling them — leaving behind his phone , keys and wallet.

Woodward picked him up and the two drove several places before winding up at the park, according to the affidavit obtained by the Orange County Register.

Woodward’s 10th-grade teacher, Philip Schwadron, remembers Woodward as “a very serious and humorless kid” who once called President Obama a “wimp” for not stationing more troops in Iraq, he told The Post.