Some of the home-recorded videos, called "The Basement Tapes", have reportedly been destroyed by police. Harris and Klebold reportedly discussed their motives for the attacks in these videos and gave instructions in bomb making. Police cite the reason for withholding these tapes as an effort to prevent them from becoming "call-to-arms" and "how-to" videos that could inspire copycat killers. Some people have argued that releasing the tapes would be helpful, in terms of allowing psychologists to study them, which in turn could possibly help identify characteristics of future killers.