David Mizen, whose son Lewis hid in a cupboard to escape gunman Nikolas Cruz, declared: “I think our confusion here, which is shared by a majority of Americans, is that if they want a handgun to protect or whatever, OK.
“If that’s in their constitution, I understand. But nobody would agree that someone buying an assault weapon, a weapon of war, let alone a disturbed 19-year-old… no one can explain to me how that makes sense at all.”
Mr Mizen, who comes from Coventry, said he was unbelievably terrified as he watched the gun rampage, in which 17 were killed, unfold on TV – knowing his son was at the Marjory Douglas Stoneman High School in Parkland but he could not contact him.
Lewis, 17, who lost a close friend in the massacre, had been ushered with his classmates into a cupboard by a teacher who then locked it to keep them safe from Cruz, who was armed with a deadly AR-15 assault rifle.
It has been dubbed “the weapon of mass murderers” after being used in a spate of attacks.
The slaughter in Parkland, a suburb on the edge of the Everglades, is the 18th school shooting this year.
Mr Mizen’s outrage has been echoed by many high school students who are are planning a mass walkout on April 20.
The youngsters took to social media to say they would not return until reforms to gun laws take place.
Florida State Attorney Pam Bondi has said she is certain prosecutors will press for the death penalty, although he is expected to plead insanity.
Whatever the killer’s fate, President Trump is facing increased pressure to toughen laws on firearms.
A rally in support of gun safety legislation outside the federal courthouse in nearby Fort Lauderdale yesterday followed Mr Trump’s visit to survivors in local hospitals with his First Lady wife Melania the night before.
The president is also under pressure to dismiss FBI Director Christopher Wray over the agency’s failure to act on a credible tip that Cruz, who bragged of his plans to carry out a slaughter, appeared on the brink of carrying out his threats.
In a statement, the FBI admitted it had been tipped off “about Cruz’s gun ownership, desire to kill people, erratic behaviour and disturbing social media posts, as well as the potential of him conducting a school shooting”.
The agency said the information, received on January 5, should have been assessed and passed on to its Miami Dade field office but “we have determined these protocols were not followed”.