The difference between this reaction, and those of both authorities and citizenry in India, is marked. Comparisons will obviously be drawn between the efficiency of the US pursuit and generally ineffective Indian efforts at investigation and control. But, in truth, that is the less important contrast. The more important difference is in the maturity of the administrative response and the degree of civic trust that was on display. In India, for example, members of the police force or the government are unlikely to have held off on speculation about a bomber's motives - out of prejudice, ignorance or media hunger. In this manhunt, too, false targets were identified - a "dark-skinned man", at first, by cable news, and then a missing Indian-American student by various internet vigilantes. The sorrow felt by the students' family reveals the pernicious nature of such speculation - but it is worth noting that law enforcement scotched those rumours fairly quickly, instead of feeding them.
It is also illustrative that the most crucial step in the apprehension of Dzhokhar Tsarnaev came when the man in whose suburban garden the fugitive teenager was hiding stepped out to have a cigarette, noticed something wrong with his boat, saw the young man curled up in a corner when he investigated - and was calling the police instantly. The greatest weapon law enforcement agencies possess is an alert and co-operative citizenry. But that requires trust - a trust that is sorely lacking between citizens and police in India. The disgraceful scenes outside the All-India Institute of Medical Sciences, where a senior policeman slapped a woman protesting the hideous rape of a five-year old girl, shows how very far India is from achieving that sort of trust. In some ways, the Delhi Police - and some other police forces - have made great strides in sensitising themselves and in being more open to the public. But the contrast visible this weekend shows how very far there is to go.