FULLERTON, Calif. (KABC) -- The search continues for Dianna Bedwell and her husband of 25 years Cecil Knutson, who have been missing since Mother's Day.
"The most important person of your life being taken away from you and not a trace left behind of their whereabouts. Just let that sink in for a second. That's where we're at," the couple's son Robert Acosta said.
Acosta believes his parents, who are both diabetic and need insulin, may have suffered a health problem and crashed somewhere.
Their mysterious disappearance is heart-wrenching for a family that's already suffered through tragedy.
About 50 years ago, Bedwell's sister Sylvia Likens, then 16, was murdered in Indianapolis. Her death was dubbed "the most terrible crime in Indiana history."
Likens was repeatedly tortured by her caretaker Gertrude Baniszewski, some of Baniszewski's children, including her daughter Paula, and other neighborhood kids.
Baniszewski was found guilty of murder in 1966.
The 2007 movie "An American Crime" was based off the infamous crime.
The couple's Fullerton neighbors just learned about the tragic past.
"It's staggering," neighbor Pat Henry said. "There's hardly words for it."
"It's unfortunate. I pray god will help us find them and in good shape," neighbor Jim Warner said.
The couple was at the Valley View Casino in Valley Center and left around 2 p.m. Sunday. They never made it to their son's home for dinner in La Quinta about 100 miles away.
They were driving a 2014 white Hyundai Sonata with the California license plate 7EHE981.
Knutson, 79, is described as 6 feet 2 inches tall, weighing 225 pounds. He has green eyes and gray hair. Bedwell, 68, is 5 feet 3 inches tall, weighing 240 pounds, with brown hair and brown eyes.
"We're very worried," neighbor Charlie Miller said. "We're wondering what's going on. Where are they?"