We are the ONLY experts to have ever won Innocence, Habeas, Dauberts and the Exclusion of both Drive Tests and Call Detail Records (CDR's).  USA v. Roderick Thornton was our first Drive Test Exclusion. USA v. Evans was our first Federal Daubert. State of Connecticut v. Emmanuel Salorio was our first Call Detail Records (CDR's) Exclusion. Lisa Roberts was our first Innocence.

We are computer programmers who have programmed the AT&T G3 Switch used to control cell towers and land lines.


Call Detail Records (CDR's) were not designed for courtroom tracking purposes and as such they are inexact. We challenge, and then modify or exclude exhibits that use Call Detail Records, Cell Hawk and Drive Test Proximity Maps. This unreliable evidence can be arranged in an endless number of theoretical but unprovable cell phone location / movement theories. We sucessfully challenge this subjective evidence even when it is presented by individuals with very convincing job titles, i.e., RF Engineers.

Some of our precedent setting cases have been discussed in the following journals: THE WASHINGTON POSTTHE NEW YORKER,  THE ABA JOURNAL, THE ECONOMISTTHE ASSOCIATED PRESS 12/11/2016 and THE ASSOCIATED PRESS 3/29/2017. 

We are proud of our groundbreaking Daubert and Innocence wins including the following:

  • UNITED STATES V. ANTONIO EVANS  -  Not Guilty.  "FBI Special Agent Raschke may not testify concerning the theory of granulization, which the court finds to be unreliable. In addition, the estimated coverage areas contained in summary exhibit 6 must be removed before the court will admit this exhibit." The Honorable Joan Humphrey Lefkow United States District Judge. Patrick Blegen of Blegen and Garvey was the lead defense attorney. 
  • LISA MARIE ROBERTS was freed after serving 12 years for a murder that she did not commit. "Petitioner shall be released from custody unless the State of Oregon elects to retry her within 90 days of the date of this Opinion and Order." The Honorable Malcolm F. Marsh United States District Judge. The Verizon RF Engineer who claimed that he could prove Lisa’s location based on her cell tower pings, elected to remain silent. Manfred Schenk and Michael Cherry were the Defense Cell Tower Experts and they worked closely with Attorney William Teesdale and other attorneys at the Portland, OR Federal Public Defender Office. 

    Mike and Manfred, 

    Lisa Roberts was released yesterday afternoon.  The DA will not
    attempt to prosecute the case again. Thank you so much for your
    work on this case. It was pretty amazing to be there to pick up Lisa
    at the prison gate as she was released after serving 12 years for a
    crime she did not commit. Cheers, William  
    William J. Teesdale
    Federal Public Defender Chief Investigator
    101 S.W. Main St., Suite 1700
    Portland, OR 97204  
  • UNITED STATES V. RODERICK THORNTON - Not Guilty.  "The Court would have significant concerns if FBI Special Agent Fitzgerald were to offer an expert opinion on the precise street location or radius where the Defendant’s phone communications were made based on the telecommunications data and methodology identified in his testimony. However, Fitzgerald clearly indicated that based on current data and cell technology infrastructure, he could not reliably offer an opinion regarding the specific location footprint indicated by the phone calls at issue here." The Honorable Amy Totenberg United States District Judge. The defense attorney was Fenn Little. 
    The Court will conference with attorneys concerning the admission of State's Exhibit 3 for trial purposes prior to trial. Modifications are necessary on Pages 7 and 8 or these pages are not admissible as part of Exhibit 3. Otherwise, FBI Special Agent Carman's Exhibit 3 is admissible, Teresa T Pulliam, Circuit Judge. We supported Defense Attorney, Christopher Daniel. 
  • STATE OF CONNECTICUT V. EMMANUEL HILDING SALORIO - Not Guilty.  The trial judge, The Honorable James Graham, excluded from evidence outdated Verizon Call Detail Phone Records (CDR's) that the prosecutor wanted to use to support his theory that Hilding Salorio was in the area of the victim's apartment on the night of the crime. The defense attorney was Hubert J. Santos.                                                             

On May 11, 2011 Adrian Deon Brown was found not guilty of murder and he walked out of the Ocala, FL County Courthouse. Prosecution experts included two Radio Frequency (RF) Engineers, one from Sprint and one from Verizon. The defense team included Attorney Nicole Hardin, Michael Cherry and Manfred Schenk.   

On December 15, 2010 Antoine Paris Davis was acquitted in the Middletown, CT Superior Court. He was charged with home invasion robbery, burglary, assault, larceny, conspiracy and accessory to kidnapping with a firearm. His defense attorney Aaron J. Romano used Manfred Schenk, as his Cell Tower Expert. The prosecution used a Verizon RF Engineer Manager.   

On Sept. 20, 2012 the employment of Messrs. Joyce, Bligh, and Cashman was reinstated by their employer National Grid. Their employment was terminated eight months earlier when outside cell phone experts accused them of stealing time based on cell tower call detail records (CDR’s). The outside cell phone experts choose not to appear at the final labor arbitration hearing as Manfred Schenk was there to challenge their interpretations.


Kylia Turner v. La Tanya E. Lee 

From: Dan Deuprey <DDeuprey@DeupreyLaw.com>
Sent: Tuesday, April 25, 2017 11:22:37 AM
To: 'Manfred Schenk'; 'Michael Cherry'; 'Michael Cherry'
Cc: Dan Deuprey; Edward J Imwinkelried
Subject: Outcome of Turner trial 

Dear Mike and Manfred: 

We received a jury verdict yesterday in favor of our client (10 to 2), and I want to again thank you both very sincerely for all of your efforts in support of our client.  By copy of this to Ed, I am also letting him know that I deeply appreciated his referral to you. 

I will be available to discuss any questions you may have, but preliminarily this is to ask that any additional invoices beyond the last received be sent to me asap for transmission to the carrier for payment. 

In addition to the benefits for our case, your work has been an interesting educational experience for me.  I hope that I may have an opportunity some day to meet Mike personally. 

Warmest regards,


Dan H. Deuprey 
1901 1st Ave., Suite 330 
San Diego, CA  92101 
Telephone:  619-757-1900


We have defeated the Call Detail Record (CDR) Business Records Exception. In some situations, it is more efficient to use a Judicial Notice of Impossibility to eliminate critical Call Detail Records. 


We have also successfully used evidence hearings including Daubert and Frye to block or modify testimony and exhibits that use the following:
Drive test
Proximity maps
Text message geolocation
Flawed tower depiction based on use of nearest/nearby tower
Flawed call records
Meta data
Sector coverage, Sector range, Sector configuration
Tower range, Tower coverage, Tower interference, Tower configuration, Nearest Tower, 


We are engaged as experts in both pre-and post-conviction cases for defendants in multiple states and federal jurisdictions across the country. Convictions, based on the location of cell phones, or the sectors that they used, should be revisited, using our unpublished newly discovered information. 


We are Biometric, Computer and Cellular Subject Matter Experts. Michael Cherry addressed the United Nations Counter-Terrorism Committee. His topic was Information Technology Security and the latest border-control systems that authenticate the identity of individuals through the use of iris or fingerprint scans. He also discussed the security implications of continuous software updates. 


Defense Attorney's Describe Cell Location Victories that We Shared - JUDICATURE Magazine    




Contact Manfred Schenk or Michael Cherry  

(201) 513-8300   



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