A judge on Tuesday directed prosecutors and lawyers for three former Penn State administrators to make their cases in writing as he weighs claims that the defendants’ legal rights were so badly violated that charges they covered up child sex-abuse allegations should be thrown out.

Dauphin County Judge Todd Hoover ruled that the defendants could not call to the stand Cynthia Baldwin, who accompanied the men to grand jury appearances in 2011 and then testified against them. Baldwin, a former state Supreme Court justice and university trustee, was Penn State’s top lawyer at the time, and the defendants believe she violated attorney-client privilege.