Patna, Dec. 23: The murder of police station chief Sanjay Kumar Tiwary in full public view yesterday was not pre-planned but the fallout of a tiff over frisking of his would-be assailants.

Preliminary investigation by the CID has revealed that Tiwary, the sub-inspector in charge of the Isuapur police station in Saran district, had entered into a quarrel with three youths who were moving about suspiciously near a railway crossing.

'The youths, who were waiting near a railway crossing after parking their motorcycle, asked Tiwary to show his identity card since he was pressuring them to undergo a body search. This led to a quarrel between the officer and the youths,' an investigating officer told The Telegraph.

One of the youths lost his nerve and fired at Tiwary, the station house officer of Isuapur police station, who insisted on frisking them. Police suspect the youths were waiting to carry out a robbery in the area. CID inspector-general Vinay Kumar said over half a dozen suspects have been detained for interrogation.