SEATTLE —Three human skulls turned up last month among the donations to a Goodwill store in Bellevue, Wash.

Employees at the store found the skulls in a donation bin. Two were placed in boxes, and one was wrapped in a striped scarf. Once workers realized the skulls were human, they reported the find to the King County Medical Examiner’s Office.

“We get a lot of unusual donations,” Goodwill spokeswoman Katherine Boury said. “We get people’s ashes in the urn. We get people’s gold teeth. And on a more positive note, last year we had someone bring in a Louis Vuitton trunk, but this is the first human skull I can remember.”

Two of the skulls were the type used for medical or educational purposes, and both were from adults, said Kathy Taylor, a forensic anthropologist with the Medical Examiner’s Office. They had been bleached, and the parts wired together.

“They looked like what you think of when you think about a skull in your biology class,” Taylor said.

The third skull is more than 100 years old and came from a native American child younger than 10 years old, according to Taylor.

“The bone is very old, very dark and very fragile,” Taylor said. “There were also cultural indications that matched native American practices.”

State law dictates that the native American skull be returned to its tribe of origin, but more information is needed to identify the correct tribe.

“Native remains are found from time to time,” Taylor said. “But usually they are found when banks by the water or forests erode. In those cases we have provenance, or a place where we know they were originally buried to return them to. But when one turns up in Goodwill, we don’t have that direction to give us an idea of where to go.”

The Medical Examiner’s Office is seeking help from the public to track down the person who donated the skulls to Goodwill so the person can provide details, without penalty, about the native American skull.

Taylor said she hopes this case will remind the public that if human remains are discovered, people should call the Medical Examiner’s Office, whether they find them in a public place or inherit them from a relative.

“It’s just the safe thing to do. Like in 2011 we had a group find a fragment of a skull on the beach and take it home, and it turned out that skull was part of a homicide case,” Taylor said.

The Medical Examiner’s Office also notes that there is a level of respect that should be shown in these cases. “A skull, even a medical skull, is still human remains and needs to be treated with respect,” Taylor said. “So you shouldn’t throw them in the trash, you shouldn’t take them home and collect them, and you definitely shouldn’t give them to Goodwill.”