May 30, 2024
Prosecutors couldn't identify a specific victim or a specific moment when Sebastian Villaseñor threatened anyone, but a judge believes he planned to kill.

Ontario Christian High student Sebastian Bailey Villaseñor posed for selfies with his father’s rifles, endlessly watched videos about school shooters, used the internet to research ammunition, body armor and police response times to name just a few, and even ordered T-shirts similar to those worn by the teens who carried out the Columbine High School massacre in 1999.

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When Ontario police interrogated the 18-year-old about his plans to shoot up his school, he laid out what he called his thoughts — where he might park, where he might open fire, how he might defend himself against police — in response to hypothetical questions such as “If you were going to do it, how would you do it?”

Sometimes he would say “I haven’t thought that far ahead” before explaining what he might do, detectives testified.

Over a two-day preliminary hearing on five counts of attempted murder that concluded Tuesday, April 16, defense attorney Daniel DeLimon solicited testimony from detectives that no one at the school felt threatened by Villaseñor — except for his sister after an argument — and that no threats had been communicated to anyone at the 475-student school despite authorities listing five specific victims.

DeLimon argued that the law on attempted murder requires not just preparation and planning, but a direct step to carry out a plot, and that the charges should be dismissed.

“We’re talking about the difference between thoughts and plans and putting plans into action and committing murder,” DeLimon said. “He had done nothing — nothing — to prepare.”

But San Bernardino County Deputy District Attorney Debbie Ploghaus noted that an Ontario police officer who examined Villaseñor’s computers testified that he found more than 4,500 related searches, downloads or texts and countered that Villaseñor’s monthslong down-the-rabbit-hole obsession with learning everything he could about carrying out a school shooting amounted to the direct step required by law to convict.

Ploghaus described the rifle selfies as “a dress rehearsal.”

Superior Court Judge Shannon L. Faherty agreed and ordered Villaseñor to stand trial.

Faherty said she believed that Villaseñor’s “thoughts” were synonymous with “plans.”

Villaseñor’s actions came to light, and the investigation began, when his 15-year-old sister, Isabella, reported them to a school counselor.

“This was a continuous course of conduct,” Faherty said in a second-floor courtroom in Rancho Cucamonga. “It started with curiosity and got to the point that it developed into an actual plan. Looking at everything as a whole, there’s a crossover between preparation and overt acts. … I’m quite certain and nervous that this plan would have come to fruition if his sister had not stepped in.”

Sebastian Bailey Villasenor, 18, sits in Rancho Cucamonga Superior Court for his preliminary hearing in Rancho Cucamonga on Thursday, April 11, 2024. The Ontario Christian High School student is accused of plotting to murder classmates. He has pleaded not guilty. (Photo by Will Lester, Inland Valley Daily Bulletin/SCNG) 


In a twist, an attempted criminal threat charge against Villaseñor — Isabella was listed as the victim — was dropped without explanation. She testified that she witnessed her brother posing with their father’s rifles in December at their Eastvale home and that he was obsessed with school shooting videos.

She said she reported him to school counselor Mitch Stutz and principal Benjamin Dykhouse on Feb. 8 to get even with him over an argument they had in the school parking lot that morning. Her brother had told her not to talk about a girl he considered a snob and then clenched his fist.

Although no expert testified that Villaseñor is autistic, his sister, school officials and detectives testified that they believe Villaseñor was “different” or “on the spectrum.”

People with autism can have “intense conversational focus on subjects that interest (them), combined with a minimal interest to engage in conversation on other topics,” according to the website They can have “the ability to focus intensely on hobbies or activities of interest. For example, (they) may be able to memorize all the facts about a popular band but have no interest in listening to the music itself.”

Without expert testimony, DeLimon treaded lightly in that area, but he suggested through his questions that autism explained Villaseñor’s obsessive research.

Villaseñor had difficulty fitting in at school because he was socially awkward, school officials testified. The five victims were four girls who had snubbed Villaseñor and a boy who was dating a girl who repeatedly rejected Villaseñor’s requests for dates. Villaseñor bowed his head and cried when a detective testified about his would-be girlfriend.

Albert Alvarado, the lead detective on the case, testified under cross-examination that he could not identify a specific individual other than Villaseñor’s sister who was a victim in this case, even though the other five were identified by name during the hearing.

“I say he threatened Ontario Christian High School,” Alvarado said.

The teens’ father, Ramiro Villaseñor, sat on a bench outside the courtroom after Tuesday’s hearing, staring at the floor for a dozen seconds before he pursed his lips and spoke.

“I’m very disappointed in the court’s decision and I think the court failed to understand how the mind of an autistic child works,” he said.

Sebastian Villaseñor is due back in court on April 25 and remains in custody in lieu of $1 million bail.