James P. Barker, the former deputy attorney general fired by Pennsylvania Attorney General Kathleen Kane shortly after he testified against her in grand jury proceedings, has sued Kane, alleging she defamed him and retaliated against him.

Barker, the former chief of the appeals unit for the Office of Attorney General, sued Kane on Monday in federal court in the Middle District of Pennsylvania. Barker said he was fired days after a newspaper article revealed he testified before the grand jury investigating whether Kane leaked information about a separate grand-jury investigation. Barker said in his complaint that his testimony “contradicted Kane’s defense” and was ultimately used by the grand jury in recommending criminal charges be filed against Kane.