A Kansas judge has ordered the state to release more documents to people fighting to write a book about the 1959 “In Cold Blood” murders.

Judge Larry Hendricks issued the order Thursday after hearing arguments over case files kept at the home of a deceased Kansas Bureau of Investigation agent who was part of the murder probe. The killings of Herb and Bonnie Clutter and two of their children became the subject of Truman Capote’s novel “In Cold Blood.”

The state filed suit to recover the files, arguing the agent’s family doesn’t own the materials. Lawyers for the family contend the state has been refusing to turn over documents it needs to defend itself against the claim.