Washington: Thursday's massacre at a Community College in Oregon was the 142nd school shooting in America since the December 2012 shooting at an elementary school in Connecticut, making for an average of nearly one a week.
As many as 88 people are killed by gun violence in America each day, according to Everytown for Gun Safety, a gun-control group founded by former New York City Mayor Michael Bloomberg, The Washington Post citing data from ShootingTracker.com said mass shootings-defined as incidents in which four or more people are shot -- have happened hundreds of times over the last several years.
In fact, during President Obama's second term, a Sunday-to-Saturday calendar week has not passed without a mass shooting incident.
Only once have seven days passed without a mass shooting and only once have eight days passed.
Those are the longest spans-the latter happening in April of this year. Several times, six days have passed.
A Congressional Research Service report published in 2013 counted 78 incidents between 1982 and 2014, in which 547 were killed, according to the Post.
About a third of all Americans with children under 18 at home have a gun in their household, including 34 percent of families with children younger than 12, according to survey data released last year by the Pew Research Centre
The most people shot in one day was on May 12, 2013, with separate mass shootings in Arizona, New Jersey, California and Louisiana, the Post said.
According to an NBC News compilation, the deadliest shooting in America was on April 16, 2007, when 23-year-old Virginia Tech student Seung-Hui Cho shot 32 people to death on the Blacksburg, Virginia, campus before killing himself.
Dec 14, 2012: Adam Lanza, 20, killed 28 people, including himself, his mother, 20 elementary school kids and six school staff and faculty at Sandy Hook Elementary School in Newtown, Connecticut.
Oct 16, 1991: George Hennard, 35, crashed his pickup through a packed restaurant in Killeen, Texas and shot and killed 23 people before shooting and killing himself.
July 18, 1984: James Huberty, 41, a former security guard who had lost his job, opened fire at a McDonald's in San Ysidro, California, killing 21 employees and customers, including children.
Aug 1, 1966: Former US Marine Charles Joseph Whitman, 25, killed his mother and wife, then went on top of a tower at University of Texas at Austin and killed 16 others.
Aug 20, 1986: Postman Patrick Henry Sherill killed 14 postal workers in Edmond, Oklahoma, and then killed himself with a shot to the head.
April 20, 1999: Students Eric Harris, 18, and Dylan Klebold, 17, killed 12 other students and a teacher at Columbine High School in Littleton, Colorado. Two dozen were injured.
Nov. 5, 2009: Nidal Malik Hasan, 39, killed 13 people and injured 32 others at Fort Hood, Texas.
April 3, 2009: Jiverly Wong, 41, an immigrant, killed 13 people and injured four others at an immigrant services centre in Binghamton, New York, before killing himself.
Feb 18, 1983: three robbers at the Wah Mee gambling club in Seattle killed 13 people.
July 20, 2012: James Holmes, 24, sprayed bullets on a midnight screening of the new Batman movie at a theater in Aurora, Colorado, killing 12 and wounding 58.
Sep 16, 2013: Aaron Alexis, 34, opened fire inside the Washington Navy Yard, killing 12. The former Navy reservist died in a gun battle with police.