Chandigarh, July 15 -- Three months after two unidentified men hurled a grenade outside the Punjab BJP headquarters in Sector 37, Chandigarh, police have filed a 1,465-page chargesheet, naming 56 prosecution witnesses, including two protected witnesses whose identities have been concealed for security reasons.

The chargesheet also reveals the use of gait analysis - the study of a person's movements while walking, including stride, abnormalities etc - for the first time by Chandigarh police.

The crude bomb was hurled at the party headquarters on April 1 but luckily, there were no casualties. It did, however, damage a parked scooter, shatter the windowpanes of a nearby car and leave splinter marks on the boundary wall.

The National Inves...