Of the 13 mass school shootings in the U.S., the three most deadly occurred in the last decade. Data from these attacks helped criminologists build a profile of the gunmen.
US school shooting experts compare Salvador Ramos to profiles of other killers dailyrecord.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from dailyrecord.co.uk Daily Mail and Mail on Sunday newspapers.
When the Columbine High School massacre took place in 1999 it was seen as a watershed moment in the United States – the worst mass shooting at a school in