LANSING, Mich. — A former prosecutor and a retired head of the Detroit FBI will play key roles in an investigation into Flint’s water crisis as part of an effort to seek answers and prevent potential conflicts of interest in the probe, Michigan’s attorney general announced today.

Bill Schuette said Todd Flood, a former assistant prosecutor for Wayne County, which includes Detroit, will spearhead Schuette’s investigation and serve as special counsel. He’ll be joined by Andy Arena, who led Detroit’s FBI office from 2007 until 2012.