FILE - This screen shot from video, shows former Michigan Gov. Rick Snyder, during his Zoom hearing in the 67th District Court in Flint, Mich., on Jan. 18, 2020. A judge had no authority to issue indictments in the Flint water scandal, the Michigan Supreme Court said Tuesday, June 28, 2022 in an extraordinary decision that wipes out charges against former Gov. Snyder, his health director and seven other people (67th District Court in Flint via AP, file)

DETROIT — Charges against former Gov. Rick Snyder and others in the Flint water scandal must be dismissed after the Michigan Supreme Court ruled Tuesday that a judge had no power to issue indictments under a century-old, rarely used law.

It’s an astonishing defeat for Attorney General Dana Nessel, who took office in 2019, got rid of a special prosecutor and put together a new team to investigate whether crimes were committed when lead contaminated Flint’s water system in 2014-15.

State laws “authorize a judge to investigate, subpoena witnesses, and issue arrest warrants” as a one-person grand jury, the Supreme Court said.

“But they do not authorize the judge to issue indictments,” the court said in a 6-0 opinion.

The challenge was filed by lawyers for former health director Nick Lyon. But the decision also applies to Snyder and others who were indicted by Genesee County Judge David Newblatt.

“This wasn’t even a close case — it was six-zip,” said Lyon attorney Chip Chamberlain. “It was based on a plain reading of the statute. They couldn’t do what they tried to do.”

There was no immediate comment from Snyder’s legal team. The attorney general’s office said it was reviewing the opinion.

In a money-saving move, Flint managers appointed by Snyder switched the city’s water source to the Flint River. State regulators said the river water didn’t need to be treated to reduce its corrosive qualities. That was a ruinous decision: Lead from old pipes flowed through the system for 18 months in the majority-Black city.

Snyder was charged with two misdemeanor counts of willful neglect of duty. Lyon and Michigan’s former chief medical executive, Dr. Eden Wells, were charged with involuntary manslaughter for nine deaths related to Legionnaires’ disease when Flint’s water system might have lacked enough chlorine to combat bacteria in the river water.

Six others were also indicted on various charges: Snyder’s longtime fixer, Rich Baird; former senior aide Jarrod Agen; former Flint managers Gerald Ambrose and Darnell Earley; former Flint public works chief Howard Croft; and Nancy Peeler, a state health department manager.