The perpetrators and victims of accidental and negligent gun discharges may be of any age. Over 120 children 15 years old or younger were killed in gun accidents in 1998.[137] Accidental injuries are most common in homes where guns are kept for self-defense.[137] The injuries are self-inflicted in half of the cases.[137] On January 16, 2013, President Obama issued 23 Executive Orders on Gun Safety,[138] one of which was for the Center for Disease Control (CDC) to research causes and possible prevention of gun violence. The five main areas of focus were gun violence, risk factors, prevention/intervention, gun safety and how media and violent video games influence the public.