To understand Michigan Attorney General Dana Nessel's decision to drop all criminal charges stemming from her predecessor's investigation of the Flint water crisis, you have to understand a couple of things:

The first thing is that it wasn't Nessel's decision — although she'll certainly bear the blame, or reap the credit, for whatever happens next in Flint.

The second thing is that most of the cases Nessel's office pulled the plug on Thursday were already on life support — and a Genesee County Circuit Court judge appeared poised to toss manslaughter charges against the highest-profile defendant, former state health director Nick Lyon, if prosecutors hadn't beaten him to the punch by folding their case.

You might imagine that the decision to drop all the charges in a criminal probe that has already lasted longer than the Watergate and Mueller investigations combined would have been taken only after Nessel, who assumed office last January, had spent weeks or months mulling her options.

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But according to her spokesperson, the new AG learned of that decision only a few hours before Fadwa Hammoud, the special prosecutor Nessel appointed to oversee the Flint criminal probe, filed a motion dismissing the eight pending cases filed by former state Attorney General Bill Schuette.

Nessel's spectator status was necessitated by her office's conflicting roles as both the prosecutor of state officials accused of criminal conduct in Flint and the defender of those sued for civil damages arising from the city's water catastrophe.

Because many of those targeted in the criminal investigation are also defendants and/or witnesses in pending lawsuits against the state, Nessel, like her predecessor, has been obliged to establish distinct chains of command for each .

Schuette chose to oversee the criminal cases himself and outsourced the defense of the Flint civil suits to his chief legal counsel, Matthew Schneider. Nessel has taken the opposite tack, assuming oversight of the civil cases and appointing Hammoud and Wayne County Prosecutor Kym Worthy, a longtime ally, to helm the criminal probe.

Preserving their options

By dismissing the charges without prejudice, Hammoud preserves three options:

• She can refile the same charges she abandoned yesterday;

• She can charge the same defendants with different crimes; or

• She can give up the state's efforts to hold some or all of the defendants criminally liable for the contamination of Flint's water supply.

So the recriminations Flint activists expressed after Thursday's announcement that Hammoud would drop the pending cases and start a new investigation are probably premature.

So is any relief Lyon and the other seven defendants may be experiencing. Hammoud's decision puts them in the clear, for now. But it also postpones the exoneration some had hoped to secure from a judge or jury.

Lyon's attorneys hadn't returned my phone inquiries by the time this column went to press, but they and their client have good reason to be incensed by Thursday's preemptive dismissal.

Schuette and Todd Flood, the special prosecutor Schuette appointed to oversee day-to-day operation of his Flint probe, charged Lyon and three other officials with involuntary manslaughter in June 2017. Prosecutors maintained that all four defendants were criminally liable for the deaths of Flint residents infected in a Legionnaires Disease outbreak prosecutors trace to the city's tainted water.

Lyon has spent most of the two years since arguing that charges against him were a part of a desperate, politically motivated effort to coerce testimony implicating his boss, former Gov. Rick Snyder. A district court judge bound him over for trial, but Lyon's attorneys, and even members of the prosecution team, believe the circuit judge presiding over the case was preparing to dismiss the manslaughter charge this week.

Hammoud's petition to dismiss the case effectively moots the more definitive dismissal ruling sought by Lyons. So he and the others charged with manslaughter charges will be denied the closure they sought, at least for the foreseeable future.

Botched discovery?

What's unclear is whether Hammoud's do-over will spawn new charges against even higher-profile defendants (like Snyder) or end in the same anti-climactic thud as her predecessor's probe.

Hammoud, who says she won't elaborate on Thursday's decision until she and Worthy meet with Flint residents later this month, has alleged in previous court filings that Flood botched discovery in the case, failing to secure or examine millions of pages of relevant devices and documents. She also maintains that Flood and assistant AGs responsible for producing evidence he subpoenaed worked in cahoots with defense attorneys for Snyder and others to limit what prosecutors could see.

Flood has declined to comment on the case since Hammoud dismissed him in April. But both defense lawyers and assistant AGs say Hammoud's explosive allegations are unfounded and calculated to buy time for prosecutors overwhelmed by the volume of documents in the case.

Although she can play no active role in the new investigation, Nessel defends Hammoud and Worthy's decision. "I trust them, and if this step is necessary for them to do a comprehensive and complete investigation, I am in absolute support.," she said in a statement.

She has little choice, in the short run; even if she thought their strategy a mistake, the new AG would have few options but to challenge the dismissal in court or fire the appointees who made it.

So like the rest of us, Nessel will have to wait and see what happens next. But either way, Bill Schuette's Flint probe is over. It's his successor's investigation now.

Brian Dickerson in the Free Press' editorial page editor. Contact him at bdickerson@freepress.com.