A search of a Salt Lake Valley landfill for clues to the whereabouts of Lori Hacking may have begun — or was at least planned by city police — as early as one day after the Salt Lake woman was reported missing by her husband last week.

Salt Lake police almost immediately asked operators of the Salt Lake Valley Solid Waste Facility to redirect trash dumping by waste collection trucks to different parts of the landfill, facility Executive Director Romney Stewart said Wednesday.

"We relocated after we got word, a day after Lori was missing," said Stewart, adding that it's been nearly 10 years since a police search was last conducted at the facility.

Police have been to the landfill, 6030 W. California Ave. (1400 South), several times in the 10 days since 27-year-old Lori Hacking disappeared. Each search — the most recent of which lasted through the night Wednesday — has employed cadaver dogs, police detective Dwayne Baird confirmed.

Trying to find anything in a place where upward of 2,500 tons of new solid waste is deposited daily is literally like looking for a needle in a haystack, Stewart added. Police have concentrated their efforts so far on an area the size of "one to two acres," he said.

Baird could not confirm what day police focused on the landfill as a possible location for either the body of the missing woman or other pieces of evidence in the case, but he said reports that the search area was so small were erroneous.

"We're looking at 20 times that amount," he said.

Police have not indicated publicly just what they might be looking for.

What does seem clear, however, is that police knew early that they had a criminal investigation on their hands.

A court document released Wednesday indicates prosecutors sought an "order of secrecy" from a 3rd District judge two days after the search for Lori Hacking began.

The order, which has not yet been granted, would effectively seal all subpoenas related to the investigation and appears to specifically protect the identity of a particular witness and any of that person's testimony. In making their case to the judge, prosecutors say that without that protection, their criminal investigation could be harmed.

Lori Hacking's husband, Mark, continues to be the only person police have named as a "person of interest" in the investigation, and no one has directly been called a suspect, although police say they are following other leads.