I am confused by reports of the perpetrator or perpetrators of the Boston blasts on April 15,2013, having used a pressure cooker bomb.
A pressure cooker bomb is a conventional type of improvised explosive device (IED) of the 1990s vintage. It can be used to cause high casualties through low intensity explosives by packing it with shrapnel. The exploding part of the cooker will add to the shrapnel effect.
The pressure cooker bomb is ideal for use in a means of transport like a bus or a train or in a public place. They easily merge with the background. In India, many people visiting towns and cities buy pressure cookers and carry them with them. Nobody suspects anything on seeing a person carrying a pressure cooker on board a train or a bus or in a public place. A terrorist finds it easy to pack it with explosives and shrapnel and leave it in a train or a bus or in a public place, where physical security is not intense.
A pressure cooker bomb does not lend itself to easy use without risk of detection on occasions like the Boston Marathon, when physical security will be tight. Evasion of physical security will be difficult. A pressure cooker near the finishing line of the Marathon would have stuck out like a sore thumb.
Why did the perpetrator or perpetrators use a pressure cooker? It is difficult to think of an explanation unless the perpetrator or perpetrators are employed in a stall near the finishing line which makes and sells snacks etc during the Marathon. Carrying a pressure cooker to the stall on the day of the Marathon may not create suspicion in the minds of the police.
One could pack a pressure cooker already in use in the stall with explosive material and shrapnel and leave it nearby during the final moments of the race when in the prevailing joy and excitement among the participants attention may not be paid to a pressure cooker kept aside.
B. Raman is Additional Secretary (retd), Cabinet Secretariat, Govt of India, New Delhi, and, presently, Director, Institute For Topical Studies, Chennai,and Associate of the Chennai Centre for China Studies. Twiiter: @SORBONNE75