Most Texas schools regularly hold emergency drills as required by law to prepare for events such as shootings, but some districts do not.
Gov. Rick Perry offered his condolences to the victims of Friday's mass shooting at a Connecticut elementary school and called for all Texas school districts to review their emergency plans.
The Legislature passed a law in 2005 that mandates that schools develop security plans and regularly practice them so that students and teachers know what to do.
"When something does happen, you hope that you've practiced it enough so that that response becomes automatic," said Fort Worth Independent School District spokesman Clint Bond.
Under the state law, schools are supposed to hold regular evacuation drills in the hallways and classrooms and conduct lockdown drills to teach students and teachers what to do if they become trapped.
"You lock the doors on the inside. You turn off the lights. You get the children away from the windows. You get them out of sight if you look in the door," Bond said.
The Texas School Safety Center surveys school districts to find out how often they rehearse their plans.
Its most recent study found that 124 of the 987 surveyed Texas districts reported that none of their schools conducted lockdown drills once per semester as recommended. Another 89 districts reported that only some of their schools held lockdown drills.
And 93 districts said none of their schools held monthly evacuation drills as recommended.
Large districts such as Fort Worth and Dallas say they conduct the drills at the recommended intervals.
"We drill for this once a month in our schools," Bond said.
The Texas School Safety Center survey found that smaller districts are sometimes less likely to complete the requirements.
The center would not name individual districts out of concern for revealing security weaknesses at specific schools.
Texas schools are also supposed to conduct a security audit once every three years. Forty districts reported that none of their facilities completed such audits. Another 10 said only some of their facilities completed the audits.
State law does not require that the people who conduct the security audits to have any kind of certification.
Districts are asked to use competent personnel, and they're given checklists of guidelines, but there currently is no certification program or designation for people conducting the audits.
The Dallas school district's police chief pointed out Friday that it's impossible to prepare for everything.
"We can do prevention," Chief Craig Miller said. "We can instruct prevention. We can have plans, but those plans can always be thwarted."