Another school banned backpacks to prevent hidden weapons from slipping through, while others changed dress codes to forbid heavy clothing such as the trench coat Pagourtzis was said to be wearing to hide his weapons.
Pagourtzis is facing capital murder charges in the deaths of eight students and two teachers.
Tisdale's mother, Cynthia Tisdale, worked a substitute teacher at Santa Fe high, and his daughter also went there, according to his statement, which was read on his behalf at a news conference on Monday. She said teachers should be armed.
The movement was reinvigorated in the wake of the Marjory Stoneman Douglas High School shooting in Parkland on Valentine's Day, which killed 17 students and teachers and wounded another 17.
Meanwhile, Pagourtzis's father told The Wall Street Journal newspaper that he suspected his 17-year-old son had been bullied in school.
The latest school shooting is unlikely to lead to significant new gun restrictions in Texas.
Galveston County Sheriff Henry Trochesset said Monday police were able to "engage" the shooter four minutes after they were called.
NFL Players Who Don't Stand For Anthem 'Shouldn't Be In The Country'
As a result, they chose to implement the rules saying that everyone needs to stand and show respect for the flag and the anthem . That's not going to play well in the locker rooms of the league, and not among a sizable contingent of the stands, either.
Gun control advocates around the country have long pressed for expanded background checks and a ban on assault rifles and high-capacity magazines, but such measures would probably have had no effect on the Santa Fe High shooting.
A recent survey from the Johns Hopkins Bloomberg School of Public Health found that just 46 percent of gun owners keep their firearms in a locked safe, cabinet or case or use other tools such as trigger locks to safely secure their weapons. Trochesset said 200 officers from law enforcement agencies throughout the region converged Friday afternoon on the shooting scene.
"Texas Republicans look at this tragedy and they do not see the gun as the problem", said Mark Jones, a political science professor at Rice University in Houston. Since 2013, Texas has reduced the cost and hours of training needed to be licensed to carry a handgun, allowed "open carry" for handgun license holders, and allowed concealed handguns in college classrooms and dorms. In 2017, he bragged about his accuracy with a pistol at a shooting range. A photograph of the governor aiming a shotgun was removed.
After yet another school shooting, Americans are once again seeking explanations - while many ignore the most obvious one. Abbott so far has committed to even less.
His spokesperson Stephen Chang said the governor was finalizing plans for the roundtables, including the dates and participants. They included measures to buy back guns, improve gun safety education and create a lethal violence protective order to stop a potentially risky person from buying or possessing a firearm.
Others questioned why the point about America's gun crime was made by comparing it to a wedding, while others pointed out the United Kingdom was also grappling with a serious spike in murder and violent crimes. I've worn a gun over 40 years.