Episode 044: Karl LNU – Cooperating Witness, Telemarketing Fraud


Karl LNU, who asked that I not use his last name (LNU stands for last name unknown – or in this case unused), was investigated, charged and convicted of bribing corrupt purchasing agents to approve invoices for over-priced and inferior lighting and maintenance supplies. In this episode of FBI Retired Case File Review, we review the case and how Karl, his business partner and their employees made telemarketing calls to unsuspecting businesses throughout the United States and ripped them off with the help of their own greedy employees. Karl pled guilty and served time for business-to-business telemarketing fraud, but his sentence was reduced significantly based on his decision to become a cooperating witness, assisting a multi-agency Group II undercover investigation targeting the business-to-business telemarketing fraud industry in the Philadelphia area. This was one of my economic crime cases. The investigation, worked in partnership with the U. S. Postal Inspection Service (USPIS) and with assistance from the Internal Revenue Service Criminal Investigative Division (IRS-CID), resulted in 16 search warrants and 25 convictions.

Karl LNU

Cooperating Witness

Business to Business Telemarketing Fraud











Here’s a pdf. compiling several news articles about separate Operation Duct Tape telemarketing fraud cases:



This giant script, which was to be recited verbatim, was on display and seized from one of the companies searched and charged with business to business telemarketing fraud by the Operation Duct Tape team.















Operation Duct Tape’s original team – Assistant United States Attorney (AUSA) Mitch Goldberg (now Federal Judge), Postal Inspector Ed Matyas, me, and AUSA Jeff Whitt.












The Bellmawr, NJ warehouse (mice not shown) where the team stored and reviewed evidence gathered during long-term undercover case.












The multi-agency team of agents and professional support staff was awarded Certificates of Appreciation by United States Attorney (USA-EDPA) Pat Meehan (now U. S. Congressman) for our dedicated , innovative and tireless efforts in the investigations and prosecutions in the telemarketing fraud Group II Undercover Case – Operation Duct Tape in November of 2004.














Jerri Williams

View posts by Jerri Williams
Jerri Williams, a retired FBI agent, author and podcaster, jokes that she writes about the FBI to relive her glory days. After 26 years with the Bureau specializing in major economic fraud and corruption investigations, she calls on her professional encounters with scams and schemers to write police procedurals inspired by true crime FBI cases in her Philadelphia FBI Corruption Squad crime fiction series featuring flawed female FBI agent Kari Wheeler. Jerri’s FBI for Armchair Detectives nonfiction series enables readers to discover who the FBI is and what the FBI does by debunking misconceptions about the FBI in books, TV, and movies. Her books are available as ebooks, paperbacks, and audiobooks wherever books are sold. She’s also the host of FBI Retired Case File Review, a true crime podcast with more than 300 episodes available on all popular podcast apps and YouTube.

1 Comment

  1. MCSeptember 14, 2022

    Hi Jerri,

    I so enjoyed this episode (#44 — I’m a newbie), because I delt with these calls in the late 80s – early 2000s! I worked one summer for my dad at the family lumber business, and he received yet another call about light bulbs. He put them on hold and told me how sick he was of these people calling. He told me to get on the phone and tell them I was responsible for all light bulbs and to keep them on the phone as long as possible. I had a good time with that! I owned several small business in the 90s and 2000s and just said “put me on your do not call list” then. I had no idea the scam was all about the “takers!” I just thought it was to sell crappy products.

    I enjoy your podcast and have shared it with friends and family. Thank you for all of your hard work and service to our country!


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