In many US states, 18 is old enough to buy a semiautomatic

  • A Broward County sheriff’s deputy escorts a protestor away from the door of the courtroom where a hearing was held for school shooting suspect Nikolas Cruz, Thursday, Feb. 15, 2018, at Broward County Court in Fort Lauderdale, Fla. Cruz is accused of opening fire Wednesday at Marjory Stoneman Douglas High School in Parkland, Fla., killing more than a dozen people and injuring several. (Charles Trainor Jr./Miami Herald via AP, Pool)

Just months after his 18th birthday, Nikolas Cruz went to a Florida gun store to buy a weapon. But there were limits on what he could purchase at his age.