There was a stretch earlier this month when a person was reported missing almost every day for a week.

EVERETT — Some families in Snohomish County are waiting for word of their loved ones.

Of the people known to have disappeared since mid-December, the whereabouts of four were still unknown Friday. There was a stretch earlier this month when a person was reported missing nearly every day for a week.

A couple of those people had a tendency to wander, a symptom of Alzheimer’s. Some disappearances appear to be tragic accidents. Others, for the moment, remain mysteries.

Shari Ireton, a Snohomish County sheriff’s spokeswoman, wonders what has happened to these people. The last unsolved missing persons case investigated by the sheriff’s office was opened more than a year ago. She has never seen so many people vanish in such a short amount of time.

On Dec. 11, a longtime letter carrier with the U.S. Postal Service left his home in Snohomish. Henry Groeneveld’s absence has mobilized dozens of people for repeated searches around town and along the Snohomish River.

Frank Urbick

A few days later — and in an unrelated case — a fisherman’s boat washed up on Hat Island. Frank Urbick, 65, hasn’t been heard from since.

That same day, a missing woman was last seen in the Trafton area of Arlington. Jessica Seybold, 39, reportedly was homeless. Detectives have little information about her disappearance, making it difficult to know where to start, Ireton said.

On Jan. 3, a Lake Stevens mother returned home to find her front door and window open, and her son gone. Jason Michael Knox White, 32,hasn’t used his credit cards or withdrawn money from his bank accounts since then. He also hasn’t used social media or email. Police believe they might have found some of his belongings in the woods Thursday.

Jessica Seybold

However, police do know what had happened to Paul Yoshiara, 75, and Rick Metzger, 65.

The two men, who were living with Alzheimer’s, had wandered from their homes. Metzger was discovered in a vacant apartment across the hall from his own. Yoshiara’s body was found in a grassy field.

Sandy Silverstein, a spokesman with the Alzheimer’s Foundation of America, said wandering is a common symptom of the disease. It also can be dangerous.

“It’s a matter of people getting lost,” Silverstein said. “They might not know who people are or where they are.”

Silverstein suggested that caregivers monitor and record their loved ones’ wandering patterns. Take note of the time of day, how long and how frequently they walk.

The behavior can be a form of communication, he said. Someone might wander in the morning because they’re hungry and looking for something to eat.

Caregivers also can install electronic chimes on doors. That way, they’ll be alerted if their loved one slips outside. They also can call the foundation’s hotline at 866-232-8484 with questions.

Jason Michael Knox White

A Snohomish County sheriff’s program expedites searches in the case that someone does go missing. Project Care Track is an electronic safety net for people who are living with Alzheimer’s, dementia, autism or other conditions that can lead someone to wander. Clients are fitted with a bracelet that emits a radio signal. A call to 911 from a caregiver triggers a response from search and rescue crews. Using signals from the bracelet, they typically find the person within an hour.

“Someone who has Alzheimer’s and is elderly or is vulnerable in some way — especially this time of year with the weather — time is going to be against them,” Ireton said.

Caitlin Tompkins: 425-339-3192; ctompkins@heraldnet.com

Share tips

Anyone with information about Henry Groeneveld or Jessica Seybold can call the sheriff’s office anonymous tipline at 425-388-3845. Information about Frank Urbick can be directed to 911.

People with tips about Jason Michael Knox White can contact Lake Stevens police at 425-212-3318 or 911.