AUSTIN, Texas -

The top law enforcement official in Texas has told lawmakers that state troopers will no longer shoot from helicopters unless they're under fire.

Texas Department of Public Safety Director Steve McCraw on Thursday announced the policy change while facing questions about two Guatemalan immigrants who were killed in October when state troopers fired on their pickup truck speeding along the U.S.-Mexico border.

State troopers mistakenly thought the truck was carrying drugs and opened fire to disable the vehicle.

McCraw still defends the shooting, saying the truck was speeding toward a school zone. But he told the House Appropriations Committee that he is now convinced "we shouldn't shoot unless being shot at, or someone being shot at."

Prosecutors are still investigating the shooting near La Joya.