An armed sheriff’s deputy on campus at Marjory Stoneman Douglas high school during last week’s deadly shooting has resigned after it emerged that he had “failed to act” to stop the massacre.

Broward County sheriff Scott Israel said yesterday that deputy Scott Peterson, who was the school resource officer, approached the building where the shooting was taking place but did not enter it or engage the gunman.

Peterson was reportedly in uniform and armed with a gun at the time of the shooting, which lasted for six minutes and killed 17 people, and had previously said that he had entered the building during the incident.

His claims were found to be false after the Broward County sheriff’s office conducted a review of security camera footage and interviewed several witnesses, including Peterson himself.

“What I saw was a deputy arrive at the west side of building 12, take up a position, and he never went in,” Israel said. The footage made him feel “sick to my stomach”, he added.

Peterson “resigned from the department on Thursday after being told he would be suspended”, The Guardian reports.

CNN says a further two deputies have been placed on restricted duty while the sheriff’s office “investigates their actions during calls to the gunman's home before the shooting”.

The sheriff’s office is conducting a review over the possible mishandling of at least 23 tips spanning nearly ten years about the shooting suspect, including one in 2017 that he was amassing a collection of knives and guns.

The New York Times says the reports have “added to a growing list of failures and missed signs” by local authorities that may have helped to prevent the shooting.