Longwood police arrested a 15-year-old boy Friday who they say brought a gun to Lyman High School in Seminole County.At about 1:30 p.m., police were called about the student causing a disturbance. The student then tried to place a backpack out of sight. He wouldn’t cooperate and was taken into custody, police say. That’s when officers say they found an unloaded gun in his backpack. No one was hurt and no threats were made to the school.WESH 2 News is not naming the teen due to his age.