Woman convicted in fatal hit-and-run collision in Laguna Beach

A 22-year-old woman was convicted Thursday of a fatal hit-and-run collision that killed a man in Laguna Beach four years ago.

Sysillia Kianna Morrison Montes De Oca was convicted of gross vehicular manslaughter, hit and run with permanent and serious injury and failing to stop at a hit and run with injury or death, all felonies. Jurors also found true a sentencing enhancement for fleeing the scene of a vehicular manslaughter.

The defendant is scheduled to be sentenced Nov. 13.

Morrison Montes De Oca was convicted of killing 60-year-old Stanley Isaacs of Costa Mesa on Aug. 11, 2022. His wife, Catherina, was also injured in the collision.

The collision happened just before 9:40 p.m. at South Coast Highway and Peal Street. According to a Laguna Beach police news release issued after the crash, the Isaacs were believed to have been in town to celebrate their anniversary.

The defendant was driving a 2009 Volkswagen Jetta when she struck the couple crossing the street, according to police.

Before the collision, the defendant told the three other passengers in the car she planned to speed up, Deputy Dist. Atty. Justin Kim said.

The prosecutor said she returned to the crime scene later with her friend and later did searches online about deadly hit-and-runs and for a TV station, Kim said.

Kim argued, “It was not an ordinary mistake,” because she was speeding and had smoked marijuana that evening. “We all know she fled the scene.”

Stanley Isaacs suffered an “internal decapitation” as well as a skull fracture, a snapped spine and “smashed ribs,” Kim said. The collision sent the victim tumbling through the air, he added.

The couple “almost survived” and got across the street at the crosswalk before the collision, Kim said.

Co-defendant Jack Francis Bannigan pleaded guilty July 9 to being an accessory after the fact for concealing the damaged car. He was sentenced to one year of informal probation and ordered to perform 120 hours of community service, according to court records.

Defense attorney Mike Molfetta argued there was no evidence in the trial that his client was smoking marijuana in the car. The group of friends “had a pizza” earlier and were driving to a beach in Aliso Viejo for night swimming, Molfetta said. They had smoked marijuana earlier but it was unclear how much time had elapsed from then until the collision.

“There’s not a single shred of testimony they were smoking in the car,” Molfetta said during closing arguments.

An expert who testified about how fast the car was going was providing an “estimate,’’ Molfetta said.

“It’s a complete waste of time because at best it gives you an estimate,” he told the jury. “You’re not here to guess. It’s about what was proven beyond a reasonable doubt.’’

Molfetta also attacked the prosecution’s argument there was a large beach crowd the night of the crash.

“He needs it to be busy because a dark, empty street means there’s no gross negligence,” Molfetta argued.

The defense attorney showed the prosecution’s photos from the crash scene to underscore his point the area was not highly populated.

Molfetta argued the prosecution was trying to smear the defendant to pave the way for a conviction.

“They need you to hate her to get a conviction,” Molfetta said.

The defense attorney accused the prosecutor of “making stuff up” to make his case.

Morrison Montes De Oca was a couple of months shy of her 19th birthday and had just started driving, Molfetta said.

She was “catatonic” after the collision and left the scene at the urging of her friends in the car, Molfetta said.

The defendant ultimately turned herself in to police.

Molfetta also pointed out the video from the scene showed another driver making an illegal U-turn that may have been a distraction.

“How fast was she going?” Molfetta asked. “We don’t know. Nobody knows, and you sure as heck don’t know.”

Daily Pilot staff contributed to this report.