Adam Lanza 's father purchased a semiautomatic Bushmaster rifle at Connecticut Gun Sales . Lanza used that gun to kill 20 children and 6 adults at Sandy Hook Elementary School . The Connecticut gun store lost its license to sell guns six days after that mass murder . A detective suspects gun sales at the store were stopped due to poor record keeping .
Adam Lanza 's mother bought a semiautomatic Bushmaster rifle at Riverview Gun Sales . Lanza used that gun to kill 20 children and 6 adults at Sandy Hook Elementary School . The Connecticut gun store lost its license to sell guns six days after that mass shooting . A detective suspects gun sales at the store were stopped due to poor record keeping .