An article published on CNN's website makes an unproven claim that pressure cooker bombs like the ones used at the Boston Marathon terror attack are a "signature" of "right-wing extremists."The article says (emphasis added) :
A senior U.S. counterterrorism investigator told CNN that pressure cooker bombs have also been a signature of extreme right-wing individuals in the United States who he said tend to revel in building homemade bombs.
This specific claim that "pressure cooker bombs have also been a signature of extreme right-wing individuals in the United States" appears to be completely unsubstantiated. Not a single example is given even in the CNN story itself of anyone other than al-Quadea using a pressure cooker bomb.
The article goes on to discuss the Olympic Park bombing by anti-abortion terrorist Erich Rudolph but those bombings were done with pipe bombs, not pressure cooker bombs. As the article says:
For example, the devices planted by Erich Rudolph at an Atlanta park during the 1996 Olympic Games were pipe bombs filled with gunpowder and nails to increase their lethality; it also had an alarm clock as a timing mechanism. Like the bombings in Boston, those devices were concealed in a backpack, according to a Department of Homeland Security report detailing the 1996 attack.
The claim in the previous paragraph was about pressure cooker bombs being a signature of right-wing extremists, not the use of pipe bombs or the more general use of a timer or a backpack.
As Breitbart News explained, instructions on how to make a pressure cooker bomb were provided in an issue of the al-Qaeda magazine Inspire.
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