Broome County District Attorney Steve Cornwell will not be allowed to act as the prosecutor in the re-trial of murder defendant Aaron Powell, according to court filings released Friday.

Judge Joseph Cawley ruled that when the DA's office hired two assistant district attorneys, it created a conflict of interest in re-trying the case. Powell, who is accused of killing his estranged wife, Christina, and her friend, Mario Masciarelli in the Town of Binghamton in March 2013, had his double-murder conviction overturned earlier this year due to an issue with a juror.

Cornwell said he was unaware that the two new hires had worked for Powell when they were brought on, and only learned of it after they began their employment.

Cawley said after an extensive search for another DA office to take over the case, he chose to appoint a private lawyer based in Binghamton. Christopher Grace, who once served as an assistant district attorney in Broome County and prosecuted high-profile cases, will prosecute Powell when the case goes to trial, which is expected to happen sometime in 2018.

Cornwell, who submitted court documents to try to retain the case, said he was disappointed that a conflict prevented him from prosecuting it.

"I am confident the defendant will be prosecuted on behalf of the victims, victims’ families, and the people of the State of New York, in a manner consistent with the high ethical standards, and legal obligations of all District Attorneys and prosecutors in this state," he said in a statement.