PORTLAND, Ore. (KOIN) – Tuesday marked the fifth day of searching for clues after two body parts were found in the Tualatin River in Hillsboro, Oregon.

The Washington County Sheriff’s Office is working under the assumption the body parts belong to the same person, but they can’t confirm they are. 

“This is really uncommon. Unsettling [and] concerning are other terms I would use to describe this incident,” said Washington County Sheriff’s Office Public Information Officer David Huey.

On Friday, Aug. 8, a kayaker found a body part floating in the river, prompting an investigation by the Washington County Sheriff’s Office and detectives from the major crimes team. But the mystery didn’t stop there. About a mile downstream, detectives found a second body part the following day. 

“There is some decomposition that’s taken place, but it looks like it’s a recent incident,” Huey said. 

Investigators are not specifying what parts of the body were found, or if they are from a man or a woman. But they are confirming that they came from an adult and are treating the investigation as a homicide.

“So we’re working under the assumption that this is going to be a fatality. So the level of injury that looks like has been sustained does appear to be not survivable,” said Huey. 

He added that authorities are “certainly” interested in finding “the rest of the person,” but couldn’t predict when that might be.

I know the search will continue, but I can’t tell you which days or what times that’s going to happen,” said Huey. 

The sheriff’s office got support from marine units, K9s, a dive team, and ground searchers from the Clackamas and Columbia County sheriff’s offices.

“It is a pretty lengthy stretch of river that … our investigators have to comb through,” said Huey.