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Cell phone data is key to cracking Berreth case, expert says

Posted at 5:13 PM, Dec 18, 2018

EL PASO COUNTY – Investigators have searched Kelsey Berreth’s home and vehicles, in addition to the home of fiancé Patrick Frazee, but the key to the case may lie in cell phone data.

That’s according to Mark Pfoff, who worked as an El Paso County Sheriff’s Deputy for 20 years before launching Rocky Mountain Computer Forensics. He’s now a court-qualified expert on cell phones and computers.

At their Dec. 10 press conference, Woodland Park Police said Kelsey’s phone sent a pair of text messages on Nov. 25, one to her boss at Doss Aviation and the other to Frazee.


Pfoff said if he was working the case, he would hone in on cell phone records, behaviors and more.

He said he’d pull her records over the last 90 days, analyzing her usage before, during and after the time she was first reported missing. If there was any significant changes, it would give investigators a place to look.

Specifically, he said looking at how the pair of texts were written, when compared to old texts, could signal suspicious activity.

“You can compare that and you can determine, does that look like her style? So the, you can kind of get the information of, did she truly send that text message, or did someone else use her phone to send that text message,” Pfoff said.

Then, there’s the reported ping on a tower near Gooding, Idaho, close to 800 miles away from Woodland Park.

Phones ping off towers in three main methods: voice calls, texts and using data.

Investigators, and the general public, are still trying to figure out the phone actually got to Idaho, especially without reaching any of the other towers along the way.

“If somebody makes a trip, you can track them very easily. They’re hitting towers on the way up,” Pfoff said.

Plus, Pfoff said there are two types of pings.

He said he thinks police received the lesser of the two, which would only tell them the phone was in the vicinity of the tower, rather than providing an exact location. Pfoff said tower radius varies among locations, ranging from two miles to as far as 45 miles.

“If it was a [true] ping, it means that the phone specifically told the tower, ‘I’m here, and here’s my location using GPS coordinates,” Pfoff said.

Additionally, the delay in reporting Berreth missing impacts the availability of cell phone data. Pfoff said investigators could have asked for what he calls a ‘tower dump’, gaining access to all of the numbers for phones that pinged off the tower that day.

However, he said towers only hold that data for three to five days. Woodland Park Police Chief Miles De Young said the texts and the ping happened on Nov. 25, but Berreth wasn’t reported missing by her mother until Dec. 2.