A list of major shooting incidents since the Dec. 14, 2012, massacre at Sandy Hook Elementary School

DEC. 12, 2014: Three students wounded outside an alternative high school in Portland, Ore., in an apparent gang dispute.

OCT. 24, 2014: Four students killed and one wounded by a classmate at Marysville-Pilchuck High School in Washington state.

JUNE 10, 2014: A 15-yearold student at Reynolds High School in Troutdale, Ore., murdered a freshman student and wounded a gym teacher before killing himself.

JUNE 5, 2014: One person killed, two wounded by shotgun-toting killer at Seattle Pacific University.

MAY 23, 2014: Six people killed and 13 wounded during rampage at Santa Barbara City College.

APRIL 2, 2014: A soldier at the Fort Hood military base killed three and wounded 16 more in a Texas shooting spree. The gunman killed himself.

JAN. 14, 2014: A 12-year-old student in Roswell, N.M., opened fire with a shotgun inside a middle school gym, wounding two other children.

DEC. 13, 2013: A Centennial, Colo., high school student critically wounded a 15-yearold classmate before killing himself. The gunman came looking to kill his debate coach.

OCT. 21, 2013: A 12-yearold middle school student gunned down a popular math teacher and two classmates with a 9-mm. handgun in Reno, Nev. The boy then killed himself. mself.

SEPT. 16, 2013: A dozen people killed and 14 wounded by a deranged gunman in the Washington Navy Yard before police shot him dead.