SAN FRANCISCO (KRON) – It’s been a week since tech executive Bob Lee was stabbed to death in San Francisco, but police are staying tight-lipped about the investigation. KRON4 spoke to renowned detective Frank Falzon about the case. 

Falzon has worked on hundreds of homicide cases – everything from the night stalker to the Zodiac killer. He has plenty of insight on why police may not be saying much about the Bob Lee case — and a whole lot more.

Lee, a well-known tech executive, was stabbed to death in San Francisco last week. Falzon says that how it all happened doesn’t sit right with him.

“Unless this was a sick psychotic killer that killed for the sheer joy, I can’t figure it out,” Falzon said. 

Falzon spent 22 years investigating more than 300 murder cases in San Francisco – the infamous “zebra killings” among them. He recounted them in his latest book “San Francisco homicide inspector 5-Henry-7” — along with the arrest of Richard Ramirez — known as the “Night Stalker.”

“We released his information and put it on the front page of every paper and news channel in the state of California. Within 24-48 hours Richard Ramirez was arrested and we put a serial killer of over 19 homicides to rest,” Falzon said.

But in Bob Lee’s case, he says police might be withholding information.

“You cannot release things in the investigation stage – things that will hurt you… There would be no reason to share the information they have that would point to a suspect at this stage unless they deem it necessary,” Falzon said. 

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But he says sometimes he says different departments and agencies involved in an investigation will disagree.

“I remember when we were working the night stalker case and the detectives down in Los Angeles wanted us to not release our information. We refused,” he remembered. 

The Daily Mail obtained exclusive surveillance video of Lee’s last moments. Police have not commented as to whether or not they may have more footage.

“They know what’s on those films, and hopefully there’s some graphic evidence and they know who could possibly have done such a crazy, insane act of stabbing somebody for no reason,” Falzon said. 

Falzon also commented on potential witnesses. 

“What I’m seeing in San Francisco is a lot of street people living on the street, constantly they’re out there day and night. If there’s any of that activity in that area I would think that these are people that investigators would be talking to. Somebody saw something,” he said. 

One thing he’s confident in is his former department’s team of investigators.

“They’re the ones that are very knowledgeable. They are the ones that will put together a picture and once they have that picture, you will know who their suspect is because they will need your help to reel them in,” he explained. 

KRON4 did ask Falzon about what he thinks the biggest technological edge police have these days — that’s DNA evidence. He says it’s like a fingerprint and something he is confident stands a good chance of helping police track down Bob Lee’s killer. 

KRON4 did reach out to SFPD again. There are still no updates, but as Falzon says, that shouldn’t be surprising.