The media groups will ask a judge Friday to ignore a request by prosecutors and George Zimmerman's attorney to keep from being released publicly the names of witnesses and some statements the neighborhood watch captain made to police.
Prosecutors and Zimmerman's attorney fear witnesses will be harassed if their names are publicized. Prosecutors also say some of Zimmerman's statements are inconsistent.
The media groups say those aren't good enough reasons to keep what is usually a public record from being released.
Zimmerman has pleaded not guilty to killing Martin and is claiming self-defense.