PARKLAND, FL. - The sheriff of the Florida county where a shooter killed 17 people at a high school last week has ordered all deputies who qualify to begin carrying rifles on school grounds.

Broward County Sheriff Scott Israel said at a news conference Wednesday that the rifles will be locked in a patrol car when not in use until the agency secures gun locks and lockers.

The sheriff said the school district's superintendent fully supports his decision.

After Stoneman Douglas shooting, Broward County deputies will now carry AR-15 rifles on school grounds, sheriff says. https://t.co/F8dfW2BKbQ pic.twitter.com/GWzk0e3KWe

— ABC News (@ABC) February 22, 2018

Marjory Stoneman Douglas High's school resource officer was carrying a weapon when the shooting happened last week but did not discharge his firearm. It's unclear what role he played in trying to thwart the shooter and whether he was aware of suspect Nikolas Cruz's past behavior at the school.

The sheriff said those details are still being investigated.