ST. LOUIS (AP) — A former Missouri Supreme Court chief justice has been chosen to sort out whether the state accessed jailhouse visitor logs and telephone recordings to get defense strategy of a man accused in the deaths of two sisters forced off an abandoned Mississippi River bridge.

A St. Louis judge appointed Mike Wolff as special master in the January death penalty retrial of Reginald Clemons, the St. Louis Post-Dispatch  reported Tuesday. Wolff will determine if the state’s attorney general’s office violated attorney-client privilege or learned identities of defense expert witnesses when it subpoenaed the jail logs and recordings of Clemons’ phone calls at the jail since March of last year.

Wolff also has served as dean of Saint Louis University’s law school.

Assistant Attorney General Christine Krug has said the state didn’t listen to any Clemons calls to public defenders, and that Clemons waived attorney-client privilege when he called his lawyers knowing the jail records calls.

Clemons spent 22 years on death row before a judge last year granted a retrial.

Clemons was one of four men convicted in the 1991 deaths of 20-year-old Julie Kerry and her 19-year-old sister, Robin. The sisters were visiting the abandoned Chain of Rocks bridge with a male cousin, Thomas Cummins, late one night when they encountered Clemons, who was 19 at the time, along with his cousin, Antonio Richardson, and two friends, Marlin Gray and Daniel Winfrey.

Prosecutors alleged the men raped the sisters and shoved them off the bridge into the river, and forced Cummins to jump. Cummins survived.

Clemons was convicted in 1993. The Missouri Supreme Court overturned the conviction in November 2015 and sent the case back to St. Louis Circuit Court.

Winfrey received a 30-year sentence in exchange for his cooperation and has since been paroled. Gray was executed in 2005. Richardson’s death sentence was commuted to life in prison without parole.