A group of concerned citizens is calling for bullet-resistant glass to become part of the school system’s security upgrade, which they also hope will include armed officers in every school.“We need levels of defense,” declared Rod McClellan, leader of the group which addressed the Warren County School Board on Thursday night.The levels of security, the former state Senate candidate said, include bullet-resistant glass since the man who killed 26 at Sandy Hook Elementary simply shot out the regular glass with his gun before he walked inside to kill 20 children and six staff members. Locks and cameras, while helping security, would not prevent such a tragedy, McClellan noted.McClellan brought an example of the bullet-resistant glass to show board members. He also had an estimate for what it would take to retrofit West Elementary, where he works as a volunteer tutor.