The bill allows parents to have a gun in a school parking lot if it is locked in a car and out of sight.
Devan Dumes faced attempted murder, theft, carjacking, and several gun-related charges.
The groups say stronger background checks would help prevent shootings like the one that took place in Newtown, Conn.
An amendment to a school safety bill creates a new position called a school protection officer and requires each school to have one.
Several members of Oath Keepers carried their guns openly during a demonstration at the Indiana capitol on Friday.
A shop owner in Bloomington says gun sales have doubled each week since the Newtown shooting.
Monroe County Community School Corporation officials are cracking down on any copycat crimes.
Greenwood recently re-discovered a city ordinance on its books that banned residents from carrying concealed weapons.
Gun deaths outnumbered fatalities in car crashes in Indiana in 2009.
A student was detained for allegedly bringing a gun to school. The weapon has not been found.