Casey Jacobson received a call from her dad on Sept. 6 that concerned her.
Her sister, Julia, hadn't spoken to him since Sept. 1 — unusual, considering she called her father in Bismarck every day from San Diego.
Messages to her sister's friends and workplace began to point to something not right, Casey Jacobson said.
"I knew since she hadn't talked to anyone in her family and her good friend and she hadn’t been communicating with anyone at her job that something was wrong," she said.
On Sept. 6, Jacobson's family filed a missing person report with San Diego Police. The next morning, police found her company car abandoned about a half-mile from her home in Normal Heights, San Diego. The car was unlocked with its windows rolled down to different levels.
"Based on the fact the car was found in that location, we don't believe she took off on her own," Casey Jacobson said. "We think something bad happened to her."
Julia Jacobson, 37, an Army veteran, was reported as last seen around 6:30 a.m. Sept. 2, at a 7-Eleven in Mission Hills, San Diego.
Video footage clocks Julia Jacobson's last sighting at 8 p.m. Sept. 2 in Ontario, Calif., said Lt. Mike Holden, of San Diego Police.
Her dog, Boogie, last seen with her then, is also missing.
Julia Jacobson's last contact was reportedly a text message to a friend about an hour later that night, Casey Jacobson said, reading, "Palm Springs today, Big Bear tomorrow."
"Big Bear" is likely in reference to a ski resort, she added.
"That's what she said. We don't know if she was there," Casey Jacobson said. "We don't know if she sent the text. We don't know."
Holden said investigators do not know where Jacobson may be, may be headed or if she is in danger.
"We have no idea and that's the tricky part about missing persons' investigations," he said. "We try to track someone's whereabouts by using the public's help and anyone calling in tips."
Casey Jacobson said her sister was transitioning to a new job at the time of her disappearance.
A Facebook page, "Help Find Julia Jacobson-San Diego Missing Person," is active, as is a GoFundMe account for the family's travel expenses and search costs. The account had raised more than $3,500 of a $20,000 goal as of noon Tuesday.
Casey Jacobson said her family has been in touch with North Dakota's congressional delegation, including Sen. Heidi Heitkamp, N.D.-D, and Rep. Kevin Cramer, N.D.-R. Friends and others have also offered support, she said.
Searching for her sister has been difficult, with family here in Bismarck and knowing few people in San Diego, according to Casey Jacobson.
Holden said police have eliminated Julia Jacobson's estranged husband as a person of interest and continue to search for her.
"Once we locate her, that will obviously give us some answers on how to proceed next," he said.
Julia Jacobson is white with blonde hair and brown eyes and weighs 150 pounds. Anyone with information may call Casey Jacobson at 701-400-9924 or San Diego Police at 619-531-2277.