WASHINGTON — President Donald Trump said Friday that the Florida sheriff’s deputy who failed to intervene in last week’s school shooting may have been a “coward,” a strong rebuke from a president toward a local law officer.

“He trained his whole life,” Trump told reporters at the White House, referring to Scot Peterson, who resigned after Broward County authorities determined he’d stood outside Marjory Stoneman Douglas High School for four minutes during the shooting that left 14 students and three teachers dead.

Trump responded to questions about his school-safety proposal to arm teachers, as reporters noted Peterson was armed yet failed to stop the carnage.

“But that’s a case where somebody was outside, they’re trained, they didn’t act properly or under pressure or they were a coward,” Trump said.

Peterson, 54, an Illinois native, broke with widely accepted police practices put in place since the 1999 Columbine High School massacre in Colorado. Instead of waiting for backup or specially trained teams to arrive, officers are trained to pursue and eliminate the threat as soon as possible in an attempt to save lives.

Broward County Sheriff Scott Israel has criticized Peterson for his inaction, saying that he should have “killed the killer.”

But one Stoneman Douglas teacher came to Peterson’s defense Thursday, arguing that the 6-foot-5-inch officer could not have stopped Nikolas Cruz, 19, who was armed with an AR-15.

“I don’t know what he could have done other than literally died,” said ninth-grade English teacher Felicia Burgin.

South Florida Sun-Sentinel, Washington Post and Associated Press contributed.

noah.bierman@latimes.com