Armed officers are now stationed in all Houston ISD schools.
Security changes are being made as students in Houston, Texas head back to classes.
Armed officers are now routinely patrolling elementary schools. According to Houston Independent School District officials, the changes were planned before the killings at Sandy Hook Elementary in Connecticut.
Armed officers had already been assigned to patrol middle and high schools.
Extra patrols have been added to cover elementary schools across HISD. The changes were made after HISD identified 14 middle and high schools with the fewest calls for service.
Officers assigned to those schools are being freed up to patrol elementary in their area during school hours, in addition to their regular patrol duties.
"As long as we've got an officer close and response time gets cut down, that is definitely a step in the right direction," said security expert Tim Wilson.