DENVER - A lawyer for the parents of two Columbine High School victims filed formal notice Thursday that they will appeal a federal judge's decision to keep statements by the gunmen's parents secret for 20 years.

U.S. District Judge Lewis T. Babcock ruled April 2 that depositions by the parents of Eric Harris and Dylan Klebold would remain sealed for 20 years. The depositions were made for a civil lawsuit that was settled out of court.

Several Columbine parents, scholars and law-enforcement officials had argued the depositions should be opened at least to researchers in hopes they could help prevent future school shootings.

Attorney Barry K. Arrington filed the notice of appeal in U.S. District Court on behalf of parents Brian Rohrbough, Susan Petrone and Dawn Anna. The notice does not discuss the grounds for appeal and Arrington did not immediately return a call.

Rohrbough and Petrone are the parents of Daniel Rohrbough and Dawn Anna is the mother of Lauren Townsend. Their children were among 12 students who were killed at Columbine on April 20, 1999.

Harris and Klebold also shot and killed teacher Dave Sanders before taking their own lives.