REDWOOD CITY, Calif. (KGO) -- Late Wednesday Belmont Police could be seen putting nearly a dozen evidence bags into the back of a patrol car.
This comes after Belmont Police, the FBI, and the San Mateo County Sheriff's office all searched a home and a park on Farm Hill Boulevard Wednesday in Redwood City for evidence in a nearly 30-year-old cold case.
Police say the search is about Ylva Hagner, a 42-year-old woman who went missing in October of 1996.
The case went cold for years, but within the past year Belmont Police started investigating it again and now it led to a search of a home and Stulsaft Park just down the street.
"Small town like Belmont, a missing person's case is near and dear to our hearts so we are looking back into and that's what brought us to Redwood City today," said Lt. Pete Lotti with Belmont Police.
Investigators were looking at a brick patio in the backyard of the home. They started removing bricks and used a robot to scan the ground. After that, they brought in digging equipment and spent Wednesday digging the section of the yard.
Records show the home belongs to Thomas Pressburger.
NASA confirmed with ABC7 that Pressburger works at the Ames Research Center as a computer scientist, and is involved in this investigation.
Neighbors described those living in the home to ABC7 News.
"Don't know them. They're one of those quiet neighbors, they keep to themselves," said Janet Healey.
"Somewhat friendly, very private," said another neighbor.
Authorities say search dogs were brought in late Wednesday afternoon to find new evidence.
"Hopefully they find something and figure it out," said Annie Norgaard, who lives down the street. "The Nextdoor app was buzzing all day. It is usually quiet here but of course we saw all the police and helicopters here today."
Neighbors say seeing images of the FBI on this property reminded them of the construction work that was done in another section of the backyard there around five years ago.
"I think there was a maybe a tractor or something that came in and they were pouring concrete for the concrete retaining wall and as a platform for a deck, and the construction went on for about a month, workers in and out of that area," said one woman.
Belmont Police tell ABC7 News that they are done with the search of the property and plan to release new information in the next day or two.
History of Ylva Hagner's Disappearance
"I just want to say come home, come home Ylva," said Hagner's brother, Bjorne Hagner in 1996.
The 42-year-old went missing on Oct. 14 of that year. She was last seen at work at a software company in Belmont. Her car was found in nearby San Carlos four days later. Her father arrived in California from Spain.
"We have no traces of her and we have all reasons to believe that this disappearance from what we know from her personality that she hasn't left her workplace by free will," said Stig Hagner in 1996.
Investigators searched Belmont's Twin Pines Park but their search turned up nothing.
"We have nothing to show that she was kidnapped, we can't find any signs of a struggle or anything like that so all we can say at this point is it's a disappearance under extremely suspicious circumstances," said Belmont Police Department Commander Larry Riche in 1996.
In 1997, investigators also searched an area in Palo Alto Hills where an acquaintance or possibly former boyfriend of Hagner's had lived.
Now, investigators are looking again decades later, in an attempt to provide long-awaited answers to her family's question, what happened to Ylva?
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