PITTSBURGH, California - Police are searching a landfill in Pittsburgh, California for a Filipino man reported missing since last weekend.

Police and search and rescue volunteers began digging through trash at the Keller Canyon Landfill in hopes of finding Frederick Sales, 35.

“This is a solemn event to be searching here. We do want to find Frederick Sales alive but we also have to follow leads as they come,” said Hercules Police spokesperson, Michelle Harrington.

Investigators believe Sales may be the fifth victim in an apparent killing spree perpetuated by Filipino, Efren Valdemoro.

Valdemoro was shot and killed by police in an Asian Supermarket in Richmond after a high speed chase on Tuesday. He was also tagged in the killings of 3 women.

Two women, Segundina Allen and Macaria Smart, both in their sixties, are Filipino. Allen and Smart were found dead in Allen’s Vallejo home on Wednesday. The other fatality is Valdemoro’s girlfiend, Cindy Tran, whom police later found dead in the suspect’s car.

The landfill is where the trash from the North Shore Business Center goes. North Shore is where Valdemoro used to work as a security guard.

“It’s a really large area so it does take a massive amount of coordination to ensure that they are searching the correct area as well as searching thoroughly,” said Harrington.

Searchers had to rummage through 3,000 tons of garbage.

“The landfill itself is a hundred acres but the area that we are operating that particular day is a very small area, less than one acre,” said Rick King, landfill manager.

Police now believe that Sales is dead as they have no other leads as to his whereabouts.

“Frederick Sales was last seen Thursday morning which was before Ricardo Sales was found. So there of course is the possibility that he was murdered at the same time as his father,” Harrington said.

Sales has been missing since August 26, a day after Valdemoro bludgeoned to death his father, Ricardo Sales, 73, in his rented Hercules home.

The elder Sales was found dead on Saturday in his Hercules home.

Frederick’s friends at the Doctors Medical Center in San Pablo said that while they are worried for his safety, there needs to be closure even if it means finding him dead.

“It’s better to know that he is found than him not being found. You know he has a family like everybody else,” said Daryl Myers, friend and patient of Sales. Balitang America