New Orleans shooting is fourth mass shooting in a year

The Mothers' Day parade shooting in New Orleans, coming less than a month after the April 15 Boston bombing, is the fourth major incident of mass shooting in the US in the last one year.

"Mass shootings are a unique feature of American life which have occurred consistently throughout history in every region of the country," according to Citizens Crime Commission of New York.

According to data compiled by the commission three previous incidents in 2012 were:

On Dec 14, Adam Lanza armed with a .22-caliber rifle killed 26 people, including 20 six and year old children at Sandy Hook Elementary School in Newtown Connecticut before shooting himself. According to police he fired over 154 shots in less than five minutes.

On Aug 5, Wade Michael Page, 40, a US Army veteran, fired 19 rounds at a Sikh Temple of Wisconsin. Page killed six Sikh worshippers and injured three, including a responding officer, before committing suicide.

On July 20, James Holmes, 24, clad in body armour and wearing a gas mask entered the Century Aurora 16 movie theatre in Aurora, Colorado during the midnight premiere screening of "Batman: The Dark Knight Rises" and killed 12 and wounded 58.

Charged with 24 counts of murder and 116 counts of attempted murder, Holmes, who remains in custody while awaiting trial, faces a minimum of life imprisonment and a maximum of death.