Ylva Annika Hagner was a resident of Palo Alto, Santa Clara County, California, United States originally from Sweden. Here are 10 more things about her:

1. She was unmarried with no known children.
2. Her brothers Bjorn Hagner and Ulf Hagner live in Stockholm, Sweden while their father Stieg Hagner live in Spain.
3. While renting a house in Palo Alto with two female roommates, she was attending Stanford University in Stanford, Santa Clara County as a graduate student and working as a business marketing manager at IXOS Software in the same building as the Belmont Police Department administration offices in Belmont, San Mateo County, California.
4. She was 5’6″ tall. Her registered weight was 110 pounds.
5. At 9:30 p.m. on October 14, 1996, she was left alone by the IXOS Software president at work to finish her shift and lock up. The president was the last person known to see her.
6. On October 15, 1996, she failed to show up for work.
7. On October 16, 1996, her friends reported her missing. She was 42 and in a romantic relationship with Thomas Pressburger of Redwood City, San Mateo County, a software program manager at the National Aeronautics and Space Administration‘s Ames Research Center in Sunnyvale, Santa Clara County.
8. On October 18, 1996, her 1992 Black Honda Civic CX Sports Wagon was found in San Carlos, San Mateo County.
9. On March 17, 1997, police used a heat sensing device to search a remote area in the Palo Alto hills for her but found no evidence to link her to the site.
10. On May 10, 2023, Federal Bureau of Investigation crime scene investigators, along with local law enforcement, searched the backyard of Pressburger’s residence in Redwood City for evidence in connection to her disappearance. The Belmont Police Department and other local agencies closed off Stulsaft Park in Redwood City to the public.