Denver ? Diaries kept by the Columbine High School gunmen are among some of the nearly 1,000 pages of documents seized from their homes and cars that will be released today, authorities said.

The documents include messages that Eric Harris and Dylan Klebold wrote in each other’s yearbooks, and a journal kept by Harris’ father, Wayne Harris.

Jefferson County Sheriff Ted Mink has said he will not release videotapes the gunmen made, for fear they would encourage copycat attacks.

The Denver Post had sued to force release of the material, and the Colorado Supreme Court last year left the decision up to the sheriff. Most of the documents are “largely irrelevant and innocuous, consisting mostly of school work,” according to a court filing by attorneys for the sheriff’s department.

Harris and Klebold killed 12 students and a teacher on April 20, 1999, before turning guns on themselves.