An Edina chiropractor and two associates were convicted this week of conspiracy and mail fraud in the second of multiple cases to grow out of a multimillion-dollar insurance fraud investigation charged by federal prosecutors late last year.

Federal authorities said Adam John Burke, 33, of Minneapolis, bilked insurance companies out of millions of dollars by billing for services that were either unnecessary or never even provided. The patients were car crash victims sent to his clinic by recruiters such as Abdirahin Khalif Ibrahim, 26, of St. Paul, and Dana Enoch Kidd, 36, of Elk River.

The three were convicted Wednesday after a two-week trial before Senior U.S. District Judge Michael Davis, who is presiding over several similar cases charged against more than two dozen metro-area defendants since December 2016.

Jurors in October convicted three other men charged with a similar scheme to commit fraud under Minnesota’s no-fault auto insurance laws.

Defense attorneys cast the cases as billing disputes between insurance providers and chiropractors rather than elaborate fraud schemes. Peter Wold, an attorney for Burke, said Thursday that he would appeal the conviction.

“I thought we had certainly established that he sent honest bills for necessary treatment,” Wold said Thursday.

Instead, jurors accepted the prosecution’s argument that Burke led a conspiracy since at least 2012 that followed a pattern mirroring other cases, which were charged after a sweeping investigation by the FBI and state Commerce Fraud Bureau.

Burke was convicted on 13 counts of fraud, including making payments of up to $2,000 to Ibrahim and Kidd for referring accident victims to his Burke Chiropractic Center. Ibrahim and Kidd, whom prosecutors described as “runners” for Burke, were also convicted of multiple fraud counts. Sentencing dates have not been scheduled.

The kickback checks to Ibrahim and Kidd were often concealed through deceptive memo lines or paid to corporate entities passing as legitimate service providers, prosecutors said, and much of the money went to patients as incentive to return to Burke’s clinic.

“In short, Burke devised a scheme that was intended to ensure that patients came for treatments at Burke Chiropractic because of the payments, as opposed to the necessity and reasonableness of the treatments,” Assistant U.S. Attorney David Maria wrote in a trial brief.

According to the U.S. Attorney’s Office, Burke wrote more than $590,000 in checks to runners during the conspiracy, and some patients were encouraged to visit his clinic up to 40 times. In a statement after the verdict, Maria said Burke’s activities “cost automobile insurers and, ultimately, policyholders in Minnesota, millions of dollars.”

The scheme “had real consequences for the people of Minnesota in terms of higher insurance costs and tax dollars spent investigating their illegal conduct,” added Richard Thornton, special agent in charge of the FBI’s Minneapolis Division, on Thursday.