WEST VALLEY CITY — For more than four years, West Valley police have been examining Josh Powell's laptops and hard drives and decrypting them, searching for any clues into the disappearance of his wife, Susan Cox Powell, whom he is suspected of killing.

Now, investigators are down to just one.

"All of the hard drives, with the exception of one that is currently being worked on by the Utah company Decipher Forensics, have been decrypted," West Valley police spokeswoman Roxeanne Vainuku said Thursday.

Whether the last hard drive can be decrypted, whether it will contain any pertinent information, and whether it's even worth the cost of decrypting were all unanswered questions Thursday.

On Dec. 6, 2009, Susan Cox Powell was last seen alive in her home when she hosted neighbors for an afternoon brunch. At 12:30 a.m. the next morning, Josh Powell told police he decided to go on a camping trip in a remote area of the west desert of Tooele County with his two boys, then ages 2 and 4, despite below freezing temperatures.

Josh Powell was considered a person of interest in his wife's disappearance almost immediately. But despite the large amount of circumstantial evidence collected against him, he was never arrested or charged.

On Feb. 5, 2012, Josh Powell attacked his sons, Charles, 7, and Braden, 5, with an ax before he killed himself and the boys in a fiery explosion at this rental home in Graham, Washington.

On May 21, 2013, West Valley police announced that while the Susan Powell case was not closed, they considered it a cold case. They would still investigate leads as they came up, police said, but all current leads had been exhausted. Powell's body has never been found.

When Susan Powell initially disappeared, police seized computer programs, hard drives and laptops from Josh Powell. According to a report from the Department of Social and Health Services in Washington, about 400 computer-generated sexual images were found on his computer.

Other laptops, however, were encrypted. Investigators have been working ever since to figure out the passwords to get into those hard drives.

"Multiple pieces of computer evidence exist in this case, including several computer hard drives. These drives have been examined by West Valley City police as well as other law enforcement, including the FBI," Vainuku said.

In all the hard drives that have been decrypted, police did not find "any material of significant evidentiary value," she said.

The final hard drive is being worked on by Decipher Forensics. On Wednesday, it was revealed that the company had successfully decoded the “first layer” of the hard drive to reach the encrypted contents of the drive. But nothing was found under that first layer of encryption.

Vainuku noted that there was no significance as to why this particular hard drive was the last to be checked, and that it was not any more or less important than the other hard drives that had already been checked.

The company, which has been working on the hard drive for free, says it continues to try and decode the next layer of encryption. But West Valley police also noted: "We continue to explore any new options that might become available to access the contents of this drive."

According to Seattle-based private investigator Rose Winquist, who is working with Susan Cox Powell's family, in order for the next layer of decryption to happen, investigators are hoping a company like internet giant Amazon could use its cloud computing platform to speed up the process.

But whether it is financially worth trying to break the encryption is a topic of discussion.

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"Breaking encryption is extremely hard, and I would say borderline impossible,” said Peter Ashdown, the CEO of Utah-based XMission.

Ashdown said new technology does make it easier to break old encryption. But a lot of that depends on how long the password is.

"It all really depends on what length of password Josh used to encrypt that hard drive. Really, the only way they can get into that encryption is by figuring out the password, and the only way they can figure out the password is by trying all the possibilities,” he said.

Powell used software called True Crypt on the drive in question. Decipher Forensics has been using a method called Brut Forcing to decrypt the hard drive, which means essentially trying every possible password.

Ashdown said it's obvious Powell was trying to hide something on his computer, and having a locked device sparks a lot of public intrigue.

"He was hiding something. Whether he was hiding his porn stash or hiding his financial documents or hiding his diary, he was keeping something that he wanted only his eyes to see,” he said.

"I would put it at a less than 1 percent chance they can crack (the code). And I don’t think they’ll find anything, because I don’t think most killers go through and diary what they’re going to do,” Ashdown said.

Vainuku also noted on Thursday, "This drive, as with other drives we have examined in the past, may hold nothing of evidentiary value."

In order to use a company like Amazon to break the code, Ashdown said it could easily cost $1 million or more. Ashdown pointed to the FBI paying a company $1 million to crack the passcode of the cellphone of Tashfeen Malik and Syed Rizwan Farook, who killed 14 people and wounded 22 in 2015 in San Bernardino. The company successfully hacked into the phone, but nothing of evidentiary value was found.

Chuck Cox, Susan Powell's father, also isn't holding his breath about how much evidence will be found on the last hard drive.

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"I don’t think (Josh) would draw a map to what he did, or anything like that," he told the Deseret News.

Using the analogy of a pot of gold at the end of the rainbow, Cox continued, "I think there’s a pot of something, but I don’t think it’s gold. I think it’s just a mess."

Cox said he's glad efforts are being made to try and decrypt the computers, but he isn't expecting it to produce major leads in his daughter's disappearance. For one, Cox believes Powell is getting too much credit for being some kind of computer genius.

"Everyone gave him more credit than he had,” he said. "He bought the latest encryption stuff that he could find and the latest programs and the latest stuff. He always liked to buy new technical stuff, computer stuff. And then he would always reformat his hard drive, like once a month. … (The encryption) wasn’t by his design, it was by his action."

Cox compared it to a fishing line that gets tangled in a ball or leaves that are scattered all over a lawn by the wind. Those types of things don't happen because of anybody's expert planning or foresight, he said.

"I don’t know how long he was planning what he was planning. I have no idea if it will be a pot of gold. Mostly I think they’re going to find out it was just a mess of string (and) there’s nothing really here worth encrypting.

"I think they’re trying to make sense out of nonsense,” Cox continued.

It's because of that, he said he was disappointed with police for trying to "outsmart" Powell.

"You can work very hard to outsmart a fool and find out he was just being foolish and there was no plan there in the beginning, ever. You can waste a whole lot of time trying to figure out why a fool does what a fool does," he said.

Cox said while he doesn't talk to West Valley police much anymore, "I’d still like to know what they really know and what they didn’t really know and see where they’ve actually searched and where they haven’t searched."

Contributing: Ladd Egan, Dave Cawley

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