There are medical conditions that can be treated with lasers. Laser eye surgery is safe and commonplace, for example. Skin disorders and arthritis pain can be treated with lasers, too. However, what you can’t do is cure every disease known to medicine by paying thousands of dollars for a handheld laser from some dude in South Dakota.

Three people were arrested and indicted [PDF] on charges related to the QLaser device, including its inventor, Robert “Larry” Lytle. The device was sold as having healing properties and able to cure every disease in existence, including ALS, HIV, diabetes, and cancer.

If you’re curious about how the QLaser was marketed back in the day, a version of the ad that ran in a Florida newspaper is available on Google Newspapers, and includes a very unimpressed-looking senior golden retriever being treated with the laser. We got the link from a snarky critique of the ad and the product written by a medical doctor.

“The use of the QLaser to treat such serious conditions is unsupported by any published clinical, scientific studies, and not approved by the U.S. Food and Drug Administration,” the U.S. Department of Justice helpfully explained in its press release about the device.

It also points out that the creator and head of the company, billed as “Dr. Larry Lytle, D.D.S., Ph.D” was no longer licensed to practice dentistry: his license had been revoked for “engaging in fraud and material deception,” and his diploma mill Ph.D was in nutrition.

Naturally, the QLaser was advertised in newspapers and targeted at the elderly, costing between $4,000 and $13,000. The government’s investigation showed that the laser could actually be dangerous if used as directed, and the people charged in the indictment are accused of continuing to sell the lasers anyway in defiance of the court order.

Since the lasers were being sent through the U.S. Postal Service, the U.S. Postal Inspection Service took the lead in the criminal investigation. A federal grand jury indicted three people associated with the company, including Dr. Lytle, with criminal contempt, mail fraud, and wire fraud. A fourth defendant, who was a QLaser distributor, pleaded guilty. [PDF]

“As the indictment alleges, these individuals targeted vulnerable citizens for years, preying on weaknesses brought about by chronic illnesses and fear of death — all to enrich themselves, and even where the scheme entailed violating a direct court order to stop,” Acting Assistant Attorney General Chad A. Readler of the Justice Department’s Civil Division said in a statement.

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