Dreaded gangster Atiq Ahmed's son Asad, wanted in the Umesh Pal murder case, was gunned down after he opened fire at a team of Uttar Pradesh Special Task Force, the chief of the unit said today. Sophisticated weapons, new cellphones and SIM cards have been recovered from Asad and co-accused Ghulam, who was also shot dead, chief of Uttar Pradesh Special Task Force Amitabh Yash said while briefing the media on the police encounter.