Friends say Jennifer Stark was a strikingly beautiful, vibrant woman who loved to laugh, a health fanatic who sweated through Spinning classes and Bikram yoga, a mother who stomached horror flicks just to spend time with her teenage kids.

The 43-year-old never missed her son's polo matches, friends said, and she was thrilled when her cheerleader daughter graduated from high school a few weeks ago.

They said Stark led impromptu exercise classes for her co-workers and encouraged them to read her favorite book, "The Secret" by Rhonda Byrne.

On Monday, employees at the Vista courthouse grieved on their first day back to work after learning that their popular colleague, a court reporter, had been slain over the weekend in what appears to have been a case of domestic violence.

"Everybody is crying," friend and co-worker Cora Sabile said. "There was a point where I was shaking and I thought I would collapse."

Stark, who worked in family and then civil law courtrooms at the Vista courthouse, had been an employee there for nine years, officials said.

A neighbor found Stark slashed to death in her Carlsbad duplex just before 11:30 p.m. Friday.

Before dawn, Stark's on-again, off-again boyfriend, Jonathan Scott French, turned himself in at the Encinitas Sheriff's Station.

On Monday, the medical examiner's office said that Stark died from a "deep, incised wound" to her neck.

"She's an absolutely wonderful, vibrant woman," Sabile said. "Why do that to her? Why? It's just tragic."

Police said witnesses had seen the couple dining at a bistro hours before the slaying.

French, 40, was arrested on suspicion of murder and is set to be arraigned Wednesday.

Because of Stark's connection to the Vista courthouse, prosecutors said the case will be handled at the courthouse in downtown San Diego.

As investigators questioned Stark's colleagues looking for clues to a motive, her friends tried to come to grips with the loss.

"People have to know what a good person she is," Sabile said. "She was really easygoing and helpful. She's that person that you don't feel awkward around."

Friends and colleagues said that Stark was not just gorgeous, but that rare combination of stunning and approachable.

She was not intimidating, pretentious, cold or really even aware of what a head-turner she was, friends said.

"She'd walk into a room and it was like the Red Sea parts and an angel enters," friend Mejkan Tague said. "The world lost a good person Friday night."

Stark loved a good, hard workout as much as a good laugh and a good bottle of red wine, Tague said.

The divorced mother of two loved spending time with her kids above all else, Tague said.

She said Stark and her ex-husband were "a prime example" of good co-parenting after they split up.

Tague, a research attorney, and Sabile, a clerk, worked with Stark in the courtroom of Judge Robert P. Dahlquist, who was on vacation Monday.

Court officials said he had been notified of Stark's slaying.

A check of court records on Monday showed that French, a salesman for a medical device company, has one prior criminal conviction in the county.

In 2005, acting as his own attorney, the Carlsbad man pleaded guilty to a misdemeanor battery charge. The court record indicates that French had been charged with spitting on and punching a man.

French was sentenced to probation and, in 2007, the court reduced the charge to an infraction for disturbing the peace.

Call staff writer Teri Figueroa at 760-740-5442.