By DeJanay Booth

DETROIT (AP) — The Michigan Supreme Court is getting more involved in Flint water criminal cases after agreeing to hear arguments in May about whether a one-person grand jury violates the state constitution.

The court on Wednesday added Nick Lyon’s case to the May 4 docket, the same day it will hear arguments about whether another defendant is entitled to additional hearings in Genesee County to challenge the evidence against her.

READ MORE: Oxford School District Hires Firm To Investigate Shooting

Nine people, including former Gov. Rick Snyder, were indicted by a judge who was serving as a grand juror while considering evidence presented by the attorney general’s office. It’s a very unusual way for prosecutors to charge people in Michigan.

Lyon, the former state health director, is charged with involuntary manslaughter under a theory that he failed to timely alert the public about a Legionnaires’ disease outbreak that was occurring when Flint was using the Flint River as a water source.

At the same time, in 2014-15, lead was contaminating the city’s water system because the water wasn’t treated to reduce its corrosive impact on old pipes.

READ MORE: 'Stop the Violence': Detroit Police Officers Host Basketball Game To Promote Peace At Schools

Attorneys for Lyon asked the Supreme Court to reach over the Court of Appeals and immediately get involved.

The one-man grand jury has “resulted in constitutional and statutory violations that are causing irreparable harm not only to these defendants but more broadly to the criminal justice process,” Chip Chamberlain and John Bursch wrote.

An email seeking comment was sent to the attorney general’s office.

MORE NEWS: Detroit Retiree Sees Sidewalk Repaired Months After Water Main Break

© 2022 Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.