HOUSTON -

Security changes are being made as Houston Independent School District students head back to classes.

Armed officers are now routinely patrolling elementary schools. According to HISD 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.

Local 2 has learned that 14 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.

HISD is not releasing the names of the schools, citing to security concerns.

"I appreciate the district trying to protect children, but the reality is they need to expand the police force," said Gayle Fallon, president of the Houston Federation of Teachers. "They need to have more people on campus."

The new security plan went into effect this week.