The Fontana Unified School District’s 14 police officers were recently armed with semi-automatic rifles,  drawing sharp criticism from some in the community who oppose having such weapons on campuses.

The Colt 6940 model rifles, which cost about $1,000 each, will be kept in on-campus safes and only be used in "extreme emergency cases" like the Newtown, Conn., massacre, said Supt. Cali Olsen-Binks.

The district purchased the rifles in October and they arrived in December, before the tragedy in Newtown, where a gunman killed 26 people — 20 of them children — at an elementary school. The shooting sparked a debate on whether armed school guards could prevent these types of tragedies.

The rifles have been on campuses since students returned from winter break in January, said Fontana Unified School District Police Chief Billy Green.