A long history of US campus gun killings

The shootings at Sandy Hook Elementary School in Connecticut are just the latest in the US’s long history of massacres at schools and colleges.

The worst in US history was the 2007 Virginia Tech massacre, when gunman Seung-Hui Cho killed 32 people and wounded 25 others before killing himself.

Four years later, Radford University student Ross Truett Ashley, 22, shot and killed a police officer on the same Virginia Tech campus before killing himself.