Editor's note: This is the fifth of a weekly series featuring highlights from a KSL investigative podcast series titled "Cold" that reports new information about the case of missing Utah woman Susan Powell.

WEST VALLEY CITY — Josh Powell did not expect West Valley police to search his minivan on Dec. 8, 2009.

Otherwise, he likely would not have left two plastic garbage bags containing possible evidence about his wife Susan’s disappearance a day earlier in the vehicle’s passenger compartment. One contained an item that has never been identified.

Detective Ellis Maxwell and his partner, Gavin Cook, first went through Powell’s minivan with his consent on the night of Dec. 7, 2009. Powell said he had returned from an overnight trip to Tooele County’s western desert hours earlier with his sons Charlie and Braden.

The minivan was cluttered with clothing, blankets and supplies. Those included a portable generator, a humidifier, hand tools and a plastic tote full of unopened camping supplies.

Maxwell and Cook also located a pink Motorola cellphone in the minivan’s center console. Cook, making an assumption, asked Powell why he had his missing wife’s phone.

“He looks and he is like a deer in the headlights and he can’t speak,” Maxwell said. “He says something to the effect of, ‘Well, I borrowed her phone yesterday because I needed cellphone numbers out of it and I must have put it in my pocket and forgot.’”

Police believe later that night Powell emptied and cleaned the minivan's interior.

Powell underwent a second interview with Maxwell the following day. At the conclusion, Maxwell told Powell he was going to serve a search warrant on the minivan. That's when Maxwell located the two sacks of garbage.

Everything police found in Josh Powell's minivan after Susan went missing

“Both of his garbage cans outside of the residence were empty so he could have easily thrown that garbage sack in the garbage cans at his residence but he chose not to," Maxwell said. "He chose to put it in his van and he was going to dispose of it elsewhere.”

The mystery item

One of the garbage sacks appeared to have come from the kitchen of the Powell home. It contained food refuse from a lunch Powell had prepared for his wife and a neighbor, JoVanna Owing, on the afternoon of Dec. 6, 2009.

“It was a theory that he poisoned or sedated Susan, whether if it was with prescription medication or whatever," Maxwell said. "We felt that he’d likely put something in her food because he’d cooked her some food that Sunday.”

However, an analysis by Utah's state crime lab failed to identify any suspicious substances among the uneaten portions.

More curious was the second garbage sack, which Maxwell recovered from a floorboard compartment. It contained several pieces of burnt drywall, which appeared to have been stacked at the time they were damaged, as well as a small metal object that had been partially melted.

During a subsequent search of the Powell home, detectives also located a scorched spot on the concrete floor of the garage.

“He did have an acetylene torch in the garage so it’s very likely that he used that torch to destroy whatever this item was,” Maxwell said.

At the time, detectives supposed the item could have been a cellphone, GPS receiver or hard drive. They sent it to an FBI lab in Quantico, Virginia, for metallurgical analysis.

The FBI determined the item was mostly steel, with calcium and strontium also present. Three short, partially melted copper wire fragments located alongside the metal object appeared to be the same style and size as those used in typical 3-prong AC power cords.

The 'Cold' experiment

In 2018, the "Cold" podcast attempted to determine the origins of the item.

"Cold" host Dave Cawley applied an oxyacetylene torch to a late 2000s-era cellphone. The device, made mostly of plastic, melted easily. It looked nothing like the metal object. Most handheld GPS units are constructed of similar materials and would presumably deform in a similar fashion.

He next applied the flame to a 3.5-inch computer hard drive, which required significantly more time and effort to destroy.

Maxwell examined the hard drive after the experiment and believed it was possible Powell’s melted object could have been a hard drive, though hard drives are not typically manufactured out of steel.

Learn more about the mystery evidence in “Cold.” Subscribe for free to the KSL podcast at www.thecoldpodcast.com. Engage with "Cold" on Facebook, Instagram and Twitter at @thecoldpodcast.