Velasco Rodriguez and his business partner dropped by the house in Canby Sunday to pick up some scrap metal they planned to salvage.
Rodriquez was killed when he opened what appeared to be a toolbox in the driveway and it exploded, The (Portland) Oregonian reported.
The violent blast shook nearby houses and could be heard for blocks, police said.
Investigators drove to Salem Tuesday to search the new home of the former Canby residents and to interview them, police said.
Police did not identify the family, which consented to the search, or say they were suspects or persons of interest.
"It's just something we have to do in the process," Canby Police Chief Bret Smith said. "It's still way too early to say what we think happened."
Meanwhile, police are studying the physical evidence, he said.
"We expect to have about 500 pieces of evidence to process," he said. "It's just huge."