A long-running telemarketing scam in which dozens of people fleeced 150,000 mostly elderly victims across the country out of $300 million would still be operating if not for the extensive help of a key perpetrator, a federal prosecutor in Minneapolis revealed this week.

Before sentencing Wayne R. Dahl Jr. to two years of supervised release, U.S. District Judge John Tunheim praised the defendant for his “extraordinary cooperation” in a decade-long investigation that led to five dozen convictions.

Dahl, 58, started Your Magazine Service, Inc. out of his home in Chaska, Minn., after finishing a prison term for selling methamphetamine. Dahl contacted his victims after purchasing sales lead lists of magazine readers who had legitimate subscriptions through other companies.

In phone calls, Dahl and his employees read from standardized sales scripts, where they pretended to work for publishers. They offered the victims one-time $150 “credits,” tricked them into handing over credit card information, and billed them for unwanted subscription packages.

The company would eventually bilk a total of $11 million from more than 13,000 people across the United States. In 2015, Your Magazine Service and similar Twin Cities-based boiler room operations drew the attention of then-Minnesota Attorney General Lori Swanson, who opened an investigation. Swanson demanded that the companies hand over their sales scripts, customer information, and phone calls that they’d recorded on analog cassette tapes.

In court on Wednesday, Assistant U.S. Attorney Joe Thompson said that nearly all of the people Swanson targeted sent her “clean” scripts and recordings where they pretended to be legitimate.

“Only one person responded with his actual scripts, the fraudulent scripts, and that’s Wayne Dahl,” Thompson said.

In 2017, a Carver County judge ordered Dahl to pay $11.5 million to resolve Swanson’s lawsuit.

“I didn’t have the money to give the victims back, but I did have the ability to stop it happening to people,” Dahl told Tunheim. “I made a lot of big mistakes in my life and this by far has to be the biggest.”

Dahl declined to be interviewed, but defense attorney Peter Wold said after the hearing that his client chose to cooperate with investigators as part of his recovery from substance abuse. Wold said that even after Dahl gave up drugs and alcohol, he continued with the fraud scheme.

“He had been physically sober for a number of years by that time, and he realized that he hadn’t been morally sober,” Wold said.

In December 2018, a grand jury indicted Dahl on charges of mail and wire fraud. Thompson said in court that he didn’t think the case would grow to involve any other defendants.

But the next month, Dahl visited the U.S. Attorney’s Office and told investigators just how extensive the scheme was.

“He admitted that he had been running a fraudulent telemarketing company, and he told us about so much more,” Thompson said.

Dahl revealed details of telemarketing companies that started in the Twin Cities and moved elsewhere, the people who owned and operated them, and how the scammers bought and sold phone scripts and “suckers lists” of potential victims.

But Dahl did more than provide information. He helped craft customer lists that included fake personas and sent those lists to associates who operated similar businesses. When scammers dialed the phone numbers on those lists, they connected with undercover postal inspectors and FBI agents. Over several years, they recorded audio of more than 1,000 phone conversations.

The investigation led to charges against 64 people. Most, including Dahl, pleaded guilty. His cooperation also included giving testimony at the 2023 trial of three defendants whom a jury ultimately convicted.

Many of the people who played minor roles in the scam received sentences of supervised release, but Tunheim sent some of the key players to prison for 10 years.

Thompson said Dahl played an important role in shutting down an entire fraudulent industry that had call center operations in 15 states, two Canadian provinces, and the Philippines.

“[It was] one of the most extraordinary and unprecedented undercover operations in the Department of Justice,” Thompson said.

Because of his criminal history and the amount of money he stole from victims, Dahl could have received a prison term of up to 20 years under federal sentencing guidelines. But because of the help Dahl provided, both prosecutors and the defense argued that Dahl should remain free.

“I’m certainly tempted to give you some time because this is a very serious crime,” Tunheim said. “I’ve seen a lot of attempts at cooperation, but I don’t think I’ve seen anything as significant as this. I think the determination to shut down this industry was extraordinarily helpful for so many people.”

Tunheim also ordered Dahl to pay restitution as income from his job as a dump truck driver allows. Before leaving court, Dahl exchanged hugs and handshakes with the prosecutors and investigators he’d been meeting with regularly over the last six years.

“I’m not the same man who committed the crimes,” Dahl said. “I no longer lie, cheat or steal to make my money. I do work an honest job and earn an honest day’s pay for an honest day’s work.”

Dahl’s sentencing hearing brings the sprawling case nearly to a close. The three final defendants to face sentencing, including a woman from Mississippi and a couple from Arizona, are due in Tunheim’s courtroom in February.