PRAYAGRAJ, July 6 -- In a letter to the family of slain sub-inspector Nebu Lal, 48, Congress national general secretary Priyanka Gandhi Vadra has expressed her deep condolences. Nebu Lal was among the eight cops who were killed in the line of duty in an encounter with criminals in Kanpur district early on Friday. The letter also said that Lal's family should be proud of his sacrifice. Local Congress leaders and workers handed over the letter to the slain cop's father Kali Prasad at his residence in Bheeti....