"Teachers want to teach, and our students want to learn. We share these same goals, and we're committed as a county to make that happen," Kamenetz said.

During the news conference, Johnson showed several weapons, including one similar to the one used at Stemmers Run. He emphasized gun safety and locking up weapons.

Johnson said the cost of gun locks range from $3 to $6 and showed several examples.

"If we find out through our investigation that the weapon was unsecured, we will charge whoever's responsible for that weapon," Johnson said.

Johnson said they have the boy in custody, and he will be charged as a juvenile. Police said his name will not be released.