CHICAGO (CBS) — Calls to arm teachers continue, nearly one month after the deadly school shooting in Parkland, Florida, including an endorsement from President Donald Trump.

Now, On Target Range & Tactical Training Center in Crystal Lake is offering free concealed carry classes to teachers.

“You have more confidence, you’re going to be safer,” said Tom Dorsch, the gun range’s operations manager. “In order to set up a deterrent, we want to offer this class to the teachers. There are teachers who want this training.”

On Target will reserve six complimentary seats for teachers in each of its regular concealed carry classes, a saving of $225. The gun range says the class is merely a first step, adding training should continue beyond the free instruction.

“In the event that something horrible happens, like someone coming into a school with a gun, there is a line of defense of teachers who are trained and have the guts to do what it takes to save the lives of our children,” Dorsch said.

President Trump threw support behind the idea of arming teachers following February’s fatal shooting of 17 people at Marjory Stoneman Douglas High School.

“Instead of advertising, this school has no guns, we are gun free. You let the people know the opposite — nobody is going to attack that school,” Trump previously said.

Christian Sandoval works information technology (IT) for schools in Grayslake. He’s one of over 50 Chicago area teachers who have already signed up for the 16-hour concealed carry training.

“It’s a good line of defense. Sometimes the police, as much as they always want to get there fast enough, they can’t. And it’s one of those things that I believe should just be a defense that we have,” Sandoval said. “We guard our banks and our money — we should protect our children just as much.”

While this particular class is filling up fast, there is opposition to the idea of arming teachers, including from the National Education Association, which is the country’s largest teachers lobby.