The Imo State Police Command said it had killed two suspected criminals who chopped off the private parts of an Assistant Superintendent of Police, Ukam Efut, at a checkpoint in Agwa in the Oguta Local Government Area of the state on Tuesday.   A statement by the command spokesperson, Micheal Abattam, in Owerri, the state capital, stated that the preliminary investigation conducted by the command suggested that the slain suspects and their fleeing accomplices were members of Eastern Security Network, the militant wing of the Indigenous People of Biafra.   Abattam also disclosed that two locally made double barrel guns