April 20, 1999: Columbine High School. Two seniors at the Colorado High School, Eric Harris and Dylan Klebold, opened fire on students in different parts of the school. The pair committed suicide inside the school in the incident most commonly referenced regarding school shootings.

April 16, 2007: Virginia Tech. In the deadliest domestic shooting incident by a single person in U.S. history, Seung Hui-Cho spread two attacks over about a two-hour period on the Virginia campus. He later killed himself.

April 3, 2009: Binghamton, N.Y. Authorities said Jiverly Wong entered the city’s immigration center and opened fire, focusing much of his attention on a classroom inside the facility. He was later found dead.

Nov. 5, 2009: Fort Hood, Texas. In the deadliest shooting ever at a U.S. military base, police said Army psychologist Nidal Hasan opened fire at the base’s processing center. Hasan was paralyzed from the waist down after being shot by police.

Jan. 8, 2011: Tucson, Ariz. U.S. Rep. Gabrielle Giffords was holding a local event when 22-year-old Jared Lee Loughner shot her in the head and fired on others at the rally. A judge, a Giffords staff member and a 9-year-old were among those killed.

Feb. 27, 2012: Chardon High School. A student later identified by other students but is a juvenile walked up to a table in the cafeteria in this Ohio school and opened fire. A teacher helped chase the shooter out of the building, and he was later arrested by police.

July 20, 2012: Aurora, Colo. During a midnight screening of the newest Batman movie, The Dark Knight Rises, 24-year-old James Holmes is accused of throwing tear gas and opened fire on the crowded theater. Police arrested Holmes at the scene.

Aug. 5, 2012: Oak Creek, Wisc. Wade Michael Page, a 40-year-old Army veteran, walked into a Sikh temple in suburban Milwaukee and opened fire. A white supremacist, Page was wounded by police before taking his own life.

Aug. 13, 2012: Texas A&M. Thomas “Tres” Caffall, 35, shot and killed a man serving an eviction notice in College Station, Texas, near the campus of Texas A&M, which caused an alert on that campus. Caffall then traded gunfire with responding police, and Caffall was killed.

Aug. 16, 2012: LaPlace, La. Two St. John the Baptist deputies were killed and two others were wounded in two separate but connected incidents. After an initial shooting in a parking lot during which a deputy was injured, deputies engaged in a gun battle with suspects, during which two were killed and suspects were apprehended.

Aug. 24, 2012: Empire State Building. Laid-off apparel designer Jeffrey Johnson, 58, shot and killed a co-worker before engaging in a gun battle with police. Johnson was killed in the gunfire.