Riverside County’s district attorney will likely be subpoenaed in a whistleblower retaliation case claiming then-District Attorney Paul Zellerbach effectively terminated a former prosecutor after he urged the office to drop murder charges in a case he believed had insufficient evidence to prosecute, following a ruling Tuesday from a California appeals court.

California’s Fourth District Court of Appeal partially vacated a court order to quash a subpoena aimed at Riverside County District Attorney Mike Hestrin. The subpoena seeks to surface alleged communications with county lawyers directing Hestrin to alter unfavorable character testimony regarding Zellerbach, whom Hestrin unseated in 2014.