Slate's Dave Cullen thought he had solved the why riddle in his article, "The Depressive and the Psychopath: At Last We Know Why the Columbine Killers Did It", published on April 20, 2004, the fifth anniversary of the massacre. Cullen wrote, "[Eric Harris] was a brilliant killer without a conscience, searching for the most diabolical scheme imaginable. If he had lived to adulthood and developed his murderous skills for many more years, there is no telling what he could have done. His death at Columbine may have stopped him from doing something worse."