Just as correctly identified DNA can show irrefutable evidence that a person committed a crime, so can forensically analyzed cell phones matched with wireless carriers’ call detail records. Modesto (Calif.) wireless expert Jim Cook will explain how on Monday, September 12, in his conference lecture entitled “Cellular Phones: The New DNA.”
The importance of cell site and sector mapping
The power of cell data mapping came to light in a 2009 homicide case on which Cook worked. Profiled in the May 2011 issue of Law Enforcement Technology, People v. Zumot showed how mapping call detail records — along with GPS data and images recovered from suspect and victim devices — can show normal patterns of behavior, broken during commission of a crime.
Cook will talk about the kind of cell site and sector mapping he did on that case and others, and why it’s relevant versus the phone’s 360-degree radius. Class participants will get a list of the verbiage he suggests investigators use when requesting carrier data, along with a discussion about why more — and faster — is better.
“This list is a result of many bloody noses that resulted from people losing evidence,” he says, “because they used incorrect words or had to write multiple search warrants, which wasted time.” In fact, he’ll be able to show a sample warrant that almost needed to be rewritten because it left out requests for key call detail record data; he’ll also show where verbiage could have been added that would have gotten better data.
Factors affecting data acquisition include services like MobileMe (soon to be iCloud) for Apple mobile devices, which enable remote wiping, and wireless carrier policies themselves, which call for limited data retention.
For himself, Cook has worked with law enforcement for a number of years, both as a consultant and as a trainer. He’s also an expert witness certified by the state of California and the federal courts. “I have a sales background, so I got to be good at explaining communications so Grandma could understand how it works,” he says. “I don’t talk to juries about control channels, data channels, bandwidth, frequencies, wireless or tower sectors; I talk about telephone lines and pie pieces.”
Hence mapping, which helps juries (along with prosecutors, judges and others) visualize data that would be very confusing if presented in raw or tabular form.
Basic and advanced cell site analysis labs
Cook will also present two labs on behalf of Micro Systemation, makers of XRY mobile forensic software. On Tuesday, September 13, his basic lab will — like his lecture — show investigators the basics about cell sites and sectors, azimuths and call detail record correlations. But it will be much more hands-on; necessary software will be pre-loaded on laptops in the lab room, and participants will spend more time mapping cell sites using Microsoft® MapPoint®, as well as manually.
The following day, Cook’s advanced lab will get into real world cases. Focusing more heavily on tower dumps and their evidentiary value, he’ll ask participants to map, as accurately as possible, small samplings of cell sites, sectors and call detail as well as SMS records from a love-triangle homicide, a gang-related homicide, and a domestic-violence homicide.
This lab will take the form of a contest, with participants separated into teams. Each team will draw one of the cases from a hat. After mapping the data, they’ll be asked to appoint a “spokesperson” to present the map and its data to the rest of the room.
“The idea is for participants to explain how they came up with their own results so that they can better understand the process that goes into mapping,” Cook explains. “That will help them meet any challenges in court.”
To learn about cell site analysis and related investigative techniques, register for the conference here. Once registered you’ll receive an email within a few weeks that will invite you to sign up for labs. Register today!
Image: locomotive8 via Flickr