Washington (CNN) The school attended by President Donald Trump's youngest son joined an open letter demanding the President pass gun legislation to protect students.

Robert Kosasky, the head of the St. Andrew's Episcopal School in Potomac, Maryland, is just one of more than 100 independent school heads in the area calling on Trump, Congress and state leaders to "enact specific, rigorous measures to reduce gun violence in our society, particularly in our schools."

The open letter, which was first published in The Baltimore Sun and obtained by CNN, pushes for a "robust system" of background checks and stronger mental health services.

The school heads also disagree with one policy Trump has been in favor of -- providing some school personnel with "rigorous" firearms training to carry guns in classrooms.

"What we do not need is to arm our teachers with guns, which is dangerous and antithetical to our profession as educators," the letter said.

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