Unsolved Casefile: Who Killed Dr. Tsunao Saitoh & Loulie Saitoh?

Posted at 10:36 AM, February 13, 2023 and last updated 1:03 PM, June 14, 2023

By: Ciara Encinas

SAN DIEGO (KGTV) — It was a warm May evening in 1996.

Dr. Tsunao Saitoh was driving his thirteen-year-old daughter, Loulie, to their secluded neighborhood around eleven o’clock at night. When they pulled into their driveway, they were shot and killed.

“We were all just so devastated,” said Phyllis Lessin.

FILE – Dr. Tsunao Saitoh (KGTV)

It was a bizarre tragedy that devastated an entire team of scientists.

Dr. Saitoh and his team were working to learn more about the brain. His co-worker Phyllis Lessin said he was on track to make a major breakthrough to help Alzheimer’s patients.

Lessin said 26 years ago she was the Assistant Chief of the Alzheimer’s disease research center at UC San Diego.

“He was just a wonderful man and I figured if anybody would get a Nobel Prize with the research it would be Dr. Saitoh,” said Lessin.

To this day, the gruesome murders bring tears to her eyes.

“Certainly at UCSD we were like a family— at the Alzheimer’s center, I mean. We were very close. We talked regularly with each other. It was just devastating. I’m sorry thinking about it just brings up such sad memories,” said Lessin.

She said she found out about the gruesome murders on the news, and the next day at work they were inundated with news cameras.

As evidence markers filled the driveway, headlines read, ‘Professional Hit?’, ‘Detectives at a loss for motive in slaying’—and ‘Widow says Saitoh was a murder target.’

“He’s not the type of person who would make enemies,” said Lessin.

At the time, investigators thought it was a hit, because of the shooters’ marksmanship.

While officers were still digging for clues, KGTV cameras rolled as his widow and the teen’s mother spoke at the services. She thanked the community for their love.

But, loved ones never expected the case to go cold.

Lots of theories were presented and people like colleagues and his wife were ruled out as suspects. To this day, investigators have no leads.

Tony Johnson is a senior investigator at the district attorney’s office.

FILE – Dr. Tsunao Saitoh (KGTV)

“No leads at all, except I would like to talk about the firearm that was used,” said Johnson.

The gun used was a Grendel P-12. A gun that was only made 1991 to 1994. It’s agun that johnson says is rare.

“They actually took a team out of rotation and tried to get test fires on every single Grendel in San Diego County, which was a huge, huge undertaking,” said Johnson.

He said what happened to the bright researcher and his daughter is a true mystery.

He is continuing to work to find out what happened to Doctor Saihto and Louile.

Johnson described the scene as he walked the driveway that remains.

“[The] car apparently pulled up here because there was broken glass in this area here that came from the driver’s side,” said Johnson.

He said people walking by found Saitoh’s car in the middle of the street with Saitoh partially hanging out of it.

Johnson thinks it’s possible that more than one person was behind the murder and those people can be tracked down.

“We have a partial DNA profile from some of the shell casings that were fired. Technology has improved to such an extent that we can get DNA from fired shell casings,” said Johnson.

Johnson said it’s enough to make a match if they can find a potential suspect.

“This is a real who done it,” said Johnson.

Nearly three decades later, the truth behind the case that Lessin never thought would go cold.

“I hope it was solved very soon after,” said Lessin.

She said she would tell her gentle coworker this if she could talk to him one last time.

“I’m so glad I had the opportunity to work with you a hundred years ago it seems. I’m sorry this happened to you. It shouldn’t have happened to you and your daughter,” said Lessin.

This story was originally published Feb. 11 by KGTV in San Diego, an E.W. Scripps Company.