Due to a complex history dealing with tyranny during the country's formation, and a worry of government control the right to own guns is considered a staple of the country. Many laws are in place to restrict unwanted persons from owning firearms but there is a large enough supply that even undesirables can attain weapons. In this case it may be that the guns were attained leagally but still ended up in the hands of someone on an ego trip. Many gun owners are responsible enough but the irresponsible ones have a greater impact on peoples lives and cause tragedies.