While it is easy to conclude that violent video games cause children to become more aggressive, perhaps there are alternative explanations to these claims. One example that involves multiple causes of aggression involves the shooting that took place in Columbine High School in Columbine, Colorado in 1999. The two shooters were high schoolers who suffered from bullying, depression, and the need of belonging. In other words, depression could be a cause of violence that is often overlooked. Eric Harris who was involve in the shootings suffered from depression, anger, and suicidal thoughts. As a result his psychiatrist proscribed him with medications that are known to increase aggression. The shooters also were both victims of bullying for many years and were struggling to feel accepted by their peers. Perhaps, violent videos are not to blame and the source of aggression lied in the choice of music the boys choose to listen to or even the choice of books they decided to read. "Research is inconclusive," emphasises Patrick Kierkegaard of the University of Essex, England. "It is possible that certain types of video game could affect emotions, views, behavior, and attitudes, however, so can books, which can lead to violent behavior on those already predisposed to violence," he states. To conclude, violent videos games can cause aggression but the effect is extremely small. In addition, only certain individuals are prone to be strongly affected by video games. In the example involving the Columbine shooting there are multiple alternative explanations. Another could include gun control laws and the availability in firearms in the United States that allow under aged children to possess such weapons.