Scott Michael Luther found himself in a deal he just couldn't close.

The 56-year-old former head of Luther Rare Coins in Minneapolis failed to execute a plea bargain with federal authorities that's been in the works since last December. As a result, a federal grand jury handed up an indictment Thursday charging Luther with defrauding customers of at least $1.5 million, and laundering some of the money through an African bank.

Luther is just the latest in string of Minnesota coin dealers who've been charged with bilking customers looking for a safe investment in the wake of the Great Recession. A Star Tribune investigation in 2011 found that the unregulated industry was rife with addicts, ex-convicts and con artists who routinely misled or defrauded customers — frequently seniors.

Luther said in a February 2011 interview that the industry was full of "corruption."

"The thing is, people get overcharged and then they send their coins and don't get what they expect they're going to get," he said. Luther said he'd been in the business since 2005 but quit working with other dealers because of what he had witnessed and started his own business by asking God for help.

"I'm in this industry also and I don't take advantage of people and I don't rob people," Luther said.

Grand jurors found probable cause to disagree. The indictment states that Luther and his small boiler room staff cold-called coin buyers around the country from 2010 through 2013, and defrauded them. In addition, the indictment charges Luther with money laundering based on a $20,000 he wired from his business bank account at Wells Fargo to Stanbic Bank of Zambia.

Luther had been expected to be arraigned and plead guilty for some time, but the hearings kept getting delayed. Douglas Altman, his attorney, recently asked to be relieved of representing Luther, citing irreconcilable differences. Luther failed to appear at an Oct. 12 hearing on the matter, and U.S. District Judge Patrick Schiltz ordered Altman to continue representing him for the time being.

Luther had sent an e-mail to Altman and Assistant U.S. Attorney Karen Schommer, who's the prosecutor on the case, saying that he was seriously ill.

"I am physically unable to make it to court. I'm so sorry, I'm not trying to avoid this, I want this behind me also," Luther wrote. "I'm having surgery on 10/17/17 which should, I'm praying that this will elevate [sic] this pain."