An NBC 5 investigation found many schools in Dallas-Fort Worth skipped important security drills designed to teach kids how to escape a fire or survive a crisis, like a gunman in their school.

For more than two years, NBC 5 Investigates has been tracking this issue and again found dozens of schools across North Texas with major gaps in their security records over the last school year.

Safety experts said schools that regularly practice drills do a better job of protecting kids.

William O’Neill, with the Texas School Safety Center, said they are lessons that can mean the difference between life and death and that if schools aren’t doing the necessary drills each semester then children aren’t being given the tools they may need to survive.

Last summer, NBC 5 Investigates requested new security records from the 20 largest school districts in North Texas and discovered many of them aren’t keeping track of how often their schools are practicing the drills or have not conducted drills required by their own district policies.

Records from Trinity High School, in the Hurst-Euless-Bedford Independent School District, show in the 2014-2015 school year they skipped nearly all security drills the district requires. In 2014, Trinity faced a lock down when police were looking for a person with a stolen gun and car near the campus.

Robert Ball is HEB’s new coordinator of Educational support services and told NBC 5 Investigates the missing security drills weren’t acceptable and wants to assure parents of students at Trinity, and other schools in HEB, that all drills will happen on schedule this year.

“I can assure them. I have already been to three of them myself. They’ve ran three drills the first three weeks of school. I’ve been to each one,” said Ball.

In the Garland Independent School District, records show almost every school had some holes in their security drill records.

Pat Lamb is the district’s new head of security. He reviewed the records from the previous school year and believes many of the schools actually did the drills but failed to document them, which he said was still unacceptable.

“Ultimately, I want to be able to look a parent in the eye and say I give you my word that on this day at this time we did that drill for your son or daughter.

More than two years ago NBC 5 Investigates found about 75 schools at The Dallas Independent School District that either didn’t record or perform security drills.

“Now I feel a lot better. After what you guys have come forward and told us, that forced us to look at our records and record keeping, and to let us know how in compliance we are and those that aren’t," said Dallas ISD Police Chief Craig Miller, in a 2013 interview with NBC 5.

However, new records from the 2014-15 Dallas ISD school year still show about 70 schools with gaps in drill records. Some, like North Dallas High School and Ann Richards Middle School, recorded no security drills at all.

Like Garland ISD, Miller thinks the drills are happening but schools are failing to record them. He believes many principals are just busy and forget to document drills. He said the district’s safer than ever after spending millions to tighten security at every school building. He just wishes principals would be better about recording drills when they take place.

“We have to put a priority on safety and have to put a priority on recognizing that we’re conducting safety drills and not letting these glaring holes show up that give the appearance that we’re not,” said Miller.

Miller anticipated that in the coming years, security records in the district would look much better. In fact, the Dallas ISD told NBC 5 Investigates that from now on a top education administrator will begin holding principals accountable on their job reviews if they don’t complete drills and write them down.

“It's not good enough to say we think we did it. We need to put pen to paper and have our facts,” said Dallas ISD Spokesman, André Riley.

At the Fort Worth Independent School District, records show 14 schools missed at least one lock down drill last year. Fort Worth ISD said it regularly reminds principals to complete those drills and is working to make sure 100 percent are conducted in the 2015-2016 school year.

While drills can’t prevent trouble, they can help kids survive.

“You need to have an understanding of what to do and have thought through that process,” said O’Neill.

Texas state law gives parents the right to see and review security drill records. Parents are encouraged to ask their children if they have done the drills and to ask the school’s principal if they have questions.