After the theory that the shooting could have been committed because of a video game was roundly rejected by experts such as Andrew Przybylsi of Oxford Internet Institute, Feggy Ostrosky Shejet of the National Autonomous University of Mexico (UNAM), Ernesto Piedras of "The Competitive Intelligence Unit", and Erik Salazar of College of Psychology of UNAM, and several media reports noted that the phrase "Natural selection" was more likely to be a reference to the Columbine High School massacre, the governor retracted his initial version.