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The Forensic Tool That Put Zetterlund Behind Bars

Photo courtesy of Cellebrite
Cellebrite's UFED Touch Device

The Aaron Zetterlund trial came to a close in early June when the 24 year old Keokuk man received a six-year prison sentence for sexually assaulting an unconscious woman during a house party in Macomb. The evidence against Zetterlund included photos and videos of the assault taking place.

Credit McDonough County Sheriff's Department
Zetterlund's mugshot.

Zetterlund’s friend Ethan Deyo, also of Keokuk, filmed the assault on his cell phone, then deleted the video. However, investigators were able to recover it.  

Lieutenant Dave Burnham of the Macomb Police Department said investigators retrieved the files using mobile forensic software from the company Cellebrite.

Burnham said the software physically extracts and analyzes data from many devices.  "Cell phones, iPods, tablets, and pretty much anything electronic that you use nowadays," he said. 

In some cases, even deleted files are still recoverable.

Buddy Tidwell, the Vice President of Global Forensic Training for Cellebrite, said mobile devices are built for speed and efficiency. Fully erasing files would cause a device to slow down significantly, so rather than deleting the entire file, the device simply removes the path leading to it.

Cellebrite’s software exploits this process in order to recover data.

Credit Johnny Cather
Macomb Police Lieutenant Dave Burnham scans his own phone with the Macomb Police Department's Cellebrite device to demonstrate its functionality.

Burnham said the Cellebrite system is the department's most used piece of data recovery technology.  It can retrieve old texts, pictures, videos, emails, calendar events, location history, and more in less than five minutes.

"I was looking at a couple of phones in the last couple of days where you could actually pinpoint the exact location that they actually took the photo," Burnham said.

The company said its product has attracted quite a bit of attention from the public.

“We get requests from people who want to buy the tool to perform an extraction of their spouse’s phone. We thank them for their interest politely but we certainly wouldn’t offer the product for that use," said Jeremy Nazarian, the Vice President of Marketing for Cellebrite USA.

Nazarian said because of privacy concerns, the software is offered only to employees of authorized military, law enforcement, and intelligence agencies.

Burnham emphasized police cannot use the technology  whenever they want. They must first obtain a warrant or the owner’s consent before searching a phone.