Not long ago it was “common knowledge in certain circles” around the Twin Cities that car crash victims could pocket some extra cash if they went to the right person, a federal prosecutor told jurors Thursday in U.S. District Court in Minneapolis.

As the first of multiple fraud trials involving metro chiropractors accused of bilking insurance companies out of millions of dollars got underway, jurors were quickly asked to consider whether they would be reviewing a case of doctors putting profit over ethics or merely the latest example of an intractable billing dispute between insurers and health care providers.

Assistant U.S. Attorney John Kokkinen told jurors that Minneapolis chiropractor Preston Forthun and a partner at his Comprehensive Rehabilitation clinic raked in more than $3 million between 2010 to 2015 from insurance companies for unnecessary treatments to patients who were frequently paid to attend up to 40 appointments each.

“The payments became the reason for getting treatment as opposed to needing it,” Kokkinen said. “This was a fraud scheme.”

Forthun is on trial alongside Abdisalan Hussein and Carlos Luna, two men he allegedly used as “runners” to recruit and pay car crash victims. All three are charged with conspiracy to commit mail and wire fraud, plus additional individual federal fraud charges in an alleged plot to take advantage of Minnesota’s no-fault insurance law.

The law mandates minimum coverage of $20,000 for medical expense benefits and other financial losses regardless of fault in a crash. More than two dozen people have been charged and additional trials are scheduled for later this year, all before U.S. District Judge Michael Davis.

Kokkinen said Thursday that Forthun and fellow chiropractor Darryl Humenny, who has since pleaded guilty to conspiracy and will testify, used “predetermined” rehabilitation plans that were “designed to make as much as possible from insurance companies.”

The doctors paid “runners” about $1,000 to $1,500 per patient recruited but withheld payments until patients attended about six to 12 appointments, Kokkinen said. All but about $100 of the money went to the patients themselves and such payments represented the clinic’s “single biggest expense.”

To keep patients returning, Kokkinen said, the doctors referred them to injury lawyers and convinced them that more visits bettered their chances at significant insurance settlements.

“The goal of the scheme was not to just break even and to recoup that big investment,” Kokkinen said. “The goal was to make money.”

Andrew Birrell, an attorney for Forthun, painted a picture of a 38-year-old self-made business owner embroiled in billing disputes with aggressive insurance companies.

“These are the types of billing disputes that permeate the insurance industry across the United States and thousands of these are resolved every day,” Birrell said. “This is not a case about the federal crimes of mail fraud and wire fraud.”

Birrell previewed a recording made by an undercover FBI agent who posed as a patient in 2014 as evidence that Forthun was direct about his approach to paying for patient referrals out of pocket. Such payments did not cost insurance companies “a single penny,” Birrell said.

Birrell said Forthun did occasionally suggest personal injury lawyers but only to protect them from aggressive litigation tactics by big insurance companies keen on not paying up.

Hussein’s attorney, R.J. Zayed, later told jurors that they would not find evidence that insurance companies were billed for medically unnecessary services or treatment never rendered.

“Not a single witness is going to come in and tell you that,” Zayed said.

Both attorneys for Hussein, a former Comprehensive Rehab patient, and Luna conceded that their clients referred people they knew or other community members to the clinic but argued that their referrals were not illegal.

Minnesota’s “runner statute,” Zayed said, “can’t shut people up and stop them” from recommending doctors. Charles Hawkins, an attorney for Luna, said his client was paid as a driver for Forthun but argued that there was no evidence Luna paid patients to visit Comprehensive Rehab. Hawkins said the only money that changed hands between Luna and a patient went toward privately covering the cost of an auto crash in an effort to avoid law enforcement.

Trial recessed Thursday amid testimony from an agent for the state’s commerce fraud bureau who said schemes like that alleged against the three men raised concerns of insurance rate hikes across the country and the prospect of crashes being staged across the metro.

The case is being closely watched by Minnesota attorneys whose own clients are awaiting trial on similar charges. Also Thursday, an attorney for chiropractor Angela Schulz sought to dismiss an indictment against her on grounds that using runners is not illegal under federal law. Paul Engh, Schulz’s attorney, pointed to a 2014 opinion in a civil case written by U.S. District Judge Patrick Schiltz, who concluded “even if kickbacks to the runners were unlawful, that does not necessarily mean the treatment provided — and the billing — was improper.”