The shootings at the Christian Oikos University in California are the latest in America's long history of murders on campus.
The worst campus massacre in American history was the 2007 Virginia Tech massacre when gunman Seung-Hui Cho killed 32 people and wounded 25 others before committing suicide.
Four years later, Radford University student Ross Truett Ashley, 22, shot and killed a police officer on the campus of Virginia Tech, before killing himself.
But the trend of school and university killings stretches back decades. In 1966, 16 people were killed and more than 30 were wounded during a 96-minute rifle rampage by student Charles Whitman at the University of Texas at Austin.
In 1970, four students were killed and nine wounded by National Guard troops dealing with anti-war protests on the campus of Kent State University in Ohio.
In 1991, Gang Lu, a graduate student in physics from China, apparently upset because he was passed over for an academic honour, opened fire in two buildings on the University of Iowa campus.
Five people were killed before the 28-year-old turned his weapon on himself.
In 1996, San Diego State University graduate engineering student Frederick Martin Davidson, 36, was defending his thesis before a faculty committee when he produced a handgun and killed three professors.
In 1999, 12 students and a teacher were murdered at Columbine High School in Colorado by two boys who then killed themselves.
And in an apparent murder-suicide in 2000, James Easton Kelly, 36, a University of Arkansas graduate student who had been dropped from a doctoral programme, and John Locke, 67, the professor overseeing his coursework, were shot dead.
In 2002, failing University of Arizona nursing student Robert Flores, 40, killed a female instructor in her office.
Minutes later, armed with five guns, the Gulf War veteran entered one of his nursing classrooms and killed two more instructors before killing himself.
The same year saw graduate student Peter Odighizuwa, 42, return to Virginia's Appalachian School of Law, from which he had been dismissed, and kill the dean, a professor and a student before being tackled by students.
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