The investigator, William Muller, has filed a "notice of claim" with the state and county against Oklahoma County District Attorney David Prater, a first step toward a possible wrongful termination lawsuit.
In the claim, Muller alleges that Prater targeted the group Oklahomans for Criminal Justice Reform because of his opposition to its proposals. The claim alleges Prater improperly obtained a grand jury subpoena without probable cause and used it to obtain financial records for the group, its chairman, and for donations made by the American Civil Liberties Union.
Prater didn't respond to requests for comment from The Associated Press, but in a statement to KFOR-TV, which first reported the claim, he called the allegations "ridiculous" and said Muller has "a personal vendetta" against him.
Oklahomans for Criminal Justice Reform, led by Republican former state House Speaker Kris Steele, has pushed proposals that include reducing criminal penalties for several nonviolent crimes and retroactively applying a state question approved by voters in 2016 that made drug possession and some property crimes misdemeanors. Prosecutors around the state have resisted such changes.
Muller's attorney, Robert Gifford, said his client was fired after he refused to continue an investigation in which no criminal file was open, no other law enforcement agencies were investigating, and state multi-county grand jury subpoenas were issued without the required probable cause.
"He was ordered to do an investigation that was an illegal investigation," Gifford said, calling Muller "a whistleblower." He also said Prater notified the Oklahoma Association of Police Chiefs of Muller's firing to prevent him from obtaining future jobs. He's asking the state attorney general's office to investigate and plans to seek the state allowed maximum of $125,000.
In his statement to KFOR, Prater said the allegations were deliberately made as he was busy "with a very important trial" and therefore "unable to fully respond." Prater is prosecuting a second-degree murder charge against an Oklahoma City police officer who fatally shot an unarmed, suicidal man in 2017. Jury selection began Monday, the day before Muller filed his notice.
Steele and the ACLU of Oklahoma issued statements saying they stand by their work on criminal justice issues.