The disappearance of Ylva Hagner has not made headlines in decades, but it was a big Bay Area story in October 1996, and the case has never been solved. Some sudden activity by FBI and police investigators Wednesday in Redwood City makes it look like there's been a break in the case.

42-year-old Swedish national Ylva Hagner was living, working, and studying in the Bay Area in 1996, with a tech marketing job in Belmont. She had a apparently been in the U.S. for 12 years, and lived in a "bohemian" household with roommates in Palo Alto. She was studying for a masters at Stanford, and was in the office at her job at IXOS Software working late on the night of October 14, 1996 when she was last seen by a coworker.

That coworker, an executive at IXOS Software, left Hagner alone in the office around 9:30 p.m. to lock up. It was a Monday night, and as the Belmont Police detective assigned to the case, Mike Speak, told the San Mateo Daily Journal back in 2000, "Ylva was working Silicon Valley type hours, coming in late, working late, so it was not unusual for her to be working that late."

Missing persons flyers starting going up after Hagner failed to show up for work for two days and her roommates had not seen her. And then her car turned up, her 1992 Black Honda Civic CX Sports Wagon, in San Carlos on Thursday. The doors were unlocked, and the keys were still in the ignition, and it was abandoned less than half a mile south of the IXOS offices. The FBI did a sweep of the car, and no forensic evidence was recovered from it.

The case had already gone pretty cold by 2000, though Detective Speak said at the time that they were still getting tips and sightings — one from as far away as Massachusetts. Covering the story in November 1996, a month after Hagner went missing, the Chronicle reported that police had questioned 30 people in the case, including several former boyfriends and Hagner's current boyfriend at the time, Tom Pressburger, a software research programmer at NASA/Ames Research center in Sunnyvale. Police said at the time that "anyone who might have been a suspect early in the investigation has produced an alibi that held up under further questioning."

It's not clear how or why there's new searching going on today, but as KPIX reports, it's happening in and around Stulsaft Park in Redwood City, as well as on some adjacent private property on the 3700 Block of Farm Hill Boulevard. The station had a helicopter flying overhead that captured video of investigators behind a residential fence, off a driveway, pulling up bricks from a walkway in preparation for digging.

Stulsaft Park was closed Wednesday morning as part of the investigation.

"The case has been refocused and we are conducting an investigation in Redwood City into the whereabouts of Ylva Hagner, in the hopes of bringing some closure in the case,"  said Belmont Police Lt. Pete Lotti in a statement.

A true-crime podcast, Trace Evidence, covered the case in 2021, and reported that there may have been an "unnecessary delay" in investigating Hagner's disappearance due to "jurisdictional confusion" over the fact that Hagner lived in Palo Alto but went missing from Belmont.

The podcast points to some allegedly suspicious emails that were sent to Hagner just prior to her disappearance from a Santa Clara University professor, Robert Collins, who became a prime suspect in the minds of Hagner's family. In the emails, Collins allegedly seemed to think he was Hagner's boyfriend, and seemed upset about her ignoring him. Hagner apparently told a coworker that Collins had been harassing her by phone, and that he had been pressuring her to have sex with him, and move in with him, and marry him, though she thought of him as "just a friend."

A Bob Collins is quoted in an early Chronicle article on the case. Calling himself a "close friend" of Hagner, Collins told the paper, "As far as I know, we have no reason to think that anything bad has happened. But I have no information to think that she's OK. We just don't know."

As the Trace Evidence podcast notes, while Collins was never charged with any crime, he reportedly, according to Hagner's family, failed a polygraph test administered by investigators, specifically on questions around Hagner's disappearance. He also apparently launched a weird investigation of his own looking for Hagner among the homeless. And, per the podcast, via a website posted by Hagner's family, "His theories about the reasons for her appearance have changed several times."

Police have never mentioned Collins as a person of interest in the case, and they have also never made any of this alleged email evidence or polygraph results public.

We'll see if today's apparent digging reveals anything further in the case, or if it's just another dead end.