Cell phones ‘key’ to finding Colorado mom Kelsey Berreth, but late missing persons report could compromise investigation: Expert

A computer forensics expert has weighed in on the case of missing Colorado mother Kelsey Berreth, who vanished on Thanksgiving Day, nearly a month ago.

Local station KOAA News 5 interviewed Mark Pfoff, founder of Rocky Mountain Computer Forensics, about the role of cell phone data in locating the 29-year-old pilot and mother of a 1-year-old girl. According to the report, Proff is a “court-qualified expert” on technical data, and worked as an El Paso County Sheriff’s Deputy for two decades.

As CrimeOnline previously reported, Berreth’s cell phone “pinged” near Gooding, Idaho — hundreds of miles from her Woodland Park home — three days after she was seen. On the same day, two text messages from her phone were sent to her employer and her fiancé, Patrick Berreth. The message to her employer reportedly said that Berreth would be taking the upcoming week off from work, and authorities have not revealed the contents of the message sent to Frazee, who did not call police about Berreth’s disappearance. Her mother Cheryl Berreth reported her missing on December 2, ten days after she was last seen on surveillance footage at a Safeway supermarket near her home.

Pfoff told the news station that if he were investigating Berreth’s disappearance, he would focus on her cell phone records and activity, examining the data from 90 days prior to when she went missing in order to detect any changes in patterns. He would pay special attention to the text messages that were sent on November 25.

“The key … is cell phone analytics,” Pfoff told KOAA.

“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,” Proff said.

Proff further explained the variations in pings that authorities can use to track cell phone use.

“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.

But there is a less specific type of ping that only indicates the general area of a cell phone, within up to a 45-mile radius According to the report, Pfoff said he believes that authorities are working with this type of signal, outside of the ping that was picked up on November 25. The report notes that no other cell phone towers between Woodland Park and an area outside of Gooding picked up any signal from Berreth’s phone, but Pfoff appears to believe this data may be incomplete.

Pfoff told the news station that he believes authorities have obtained cell phone tracking data from a “tower dump,” which lists all of the phones that have been detected by a specific cell phone tower. The report indicates that the messages sent from Berreth’s phone would have sent authorities more specific location information than data obtained from the tower dump, adding that towers typically hold data for only three to five days.

The suggestion is that the delay in reporting Berreth missing may mean that tower dump data from previous days was not available when authorities began their investigation, and that authorities would not have been able to use the data to determine if anyone was with Berreth when the text messages were sent.

As KOAA reporter Sam Kraemer, who interviewed Pfoff, noted in a tweet, “Had police known she was missing on Nov. 25, they could’ve pulled all tower data to see if there was other CO phone numbers possibly w/hers.”

CrimeOnline will provide further updates when more information is available.