"Using surveillance footage, Port Angeles police spotted Backer or someone who looked like Backer leaving the Coho ferry, making a left onto East First Street and riding “further up into PA."

Sounds like they suspected Backer had come to PA, but couldn't prove it. Yet he would have cleared US Customs when getting off the ferry, so Customs would know with certainty whether he was (or was not) there. But based on this article, the PA police only had questionable surveillance footage. 

Taken at face value, it sounds like Border Patrol and PA don't share information. 

Either that, or this is an artifact of poor PDN reporting.