WASHINGTON -- Last September, a Flint lawmaker asked Bill Schuette, Michigan's attorney general, to investigate whether government officials were to blame for exposing the city's citizens to dangerously high levels of lead in their drinking water. Schuette -- a Republican widely believed to have ambitions of running for governor in 2018 -- refused.

"Given the multiple reviews by federal and state agencies, and the pending and potential federal court actions, we do not believe it necessary to conduct an additional investigation," a Schuette staffer wrote on Dec. 22, almost three months after state Rep. Sheldon Neeley (D-Flint) sent his request.

But in the weeks after Schuette refused to investigate, national media attention on Flint increased, and on Jan. 14, Republican Governor Rick Snyder asked President Barack Obama to declare a federal emergency. The next day, Schuette had changed his tune. He said that he would launch an investigation "without fear or favor."

Schuette already represents some of the same people his office could end up investigating. His office is defending state officials in a lawsuit in which Flint citizens allege that state and local government officials ignored evidence that the water pumped from the Flint River was toxic and caused serious injury.

The lawsuit also names as defendants two of the state-appointed emergency managers who were in charge of Flint in 2014 and opted to use the Flint River as its water supply. Under state law, the attorney general has to represent emergency managers when they're sued, but the town the emergency manager ran has to cover the legal costs.

"The people of Flint -- who have been forever harmed by a succession of state-appointed managers -- now have no fair legal recourse from someone who is supposed to be the people's lawyer," state Sen. Jim Ananich (D-Flint) said in an emailed statement.

The people of Flint... now have no fair legal recourse from someone who is supposed to be the people's lawyer. State Sen. Jim Ananich

It's not unusual for state attorneys general to find themselves on different sides of the same case, said James Tierney, director of the National State Attorneys General Program at Columbia Law School.

"Attorneys general do this all the time," Tierney told The Huffington Post. Without commenting on Michigan specifically, Tierney said attorneys general have a lot of options for mitigating the appearance of a conflict. They could bring in outside counsel to handle a case, or have different lawyers within their office handle defense and prosecution. Schuette's office did not comment on whether it has taken the latter approach.

In high-profile cases such the Flint water crisis, the attorney general could be personally involved in both the investigation and the lawsuit, said Bruce Green, the director for the Louis Stein Center for Law and Ethics at Fordham Law School. Tierney pointed to a case in which the late Beau Biden, who was serving as Delaware's attorney general, abruptly switched from defending an embattled psychiatric center to investigating it.

"The way the system is set up, that happens quite frequently, where the attorney general has attorneys on both sides," said state Sen. Rick Jones (R). "I certainly think the attorney general of Michigan should investigate everything that went on, and if there was anybody at the [Michigan Department of Environmental Quality] that changed information or covered up information, if it's criminal, then certainly the attorney general should take action."

Deborah LaBelle, an attorney for the plaintiffs suing Michigan, nonetheless questioned whether Schuette can conduct an independent investigation when he's defending the state against charges of wrongdoing. "What is the attorney general doing investigating his clients?" she asked. "It doesn't even make sense."

Schuette's investigation only arrived when it was the "popular thing to do," said Nic Clark, the Michigan director of Clean Water Action, which promotes clean, safe and affordable water. "We want to know whose side is he really on."

"Bill Schuette’s biggest priority is Bill Schuette, so he will do whatever he thinks makes sense in his desire to succeed Rick Snyder as governor," said David Holtz, executive committee chair for the Michigan chapter of the Sierra Club, which called for an independent investigation in October. "The least likely thing Bill Schuette will do is to mount an aggressive pursuit of the facts," he added.

Schuette's office declined to provide comment for this story and would not say which Flint-related lawsuits the attorney general is defending.