84-year-old Jose Navarro and 87-year-old Rafaela Guzman Navarro

He says they've sent potential evidence to the state crime lab and are now awaiting the results.

Police say they were called by family members who had stopped to check on their grandparents but found the couple "had been critically injured."

Authorities say they were called to a home in the 1100 block of Whatcom Street in Union Gap at about 10:30 pm Monday.