Chennai, July 14 (Reporter) One of the key accused, Thiruvengadam (33), a history sheeter, involved in the murder of BSP Tamil Nadu Unit President K Armstrong, was killed in a police encounter on Sunday morning near Madhavaram in North Chennai. Meanwhile, the Opposition AIADMK an the BJP raised suspicions over the encounter on the ground that Thiruvengadam, who had surrendered before the police after the murder, had tried to escape from police. Armstrong was murdered on the night of July 5 by a six-member gang in front of his Perambur residence. The killing created a political furore across the country and BSP Supremo and former Uttar Pradesh Chief Minister Mayawati flew down to Chennai to pay her last respects to him. Though the State government immediately ordered a CB-CID probe into the murder, Ms Mayawati claimed that the real culprits were not arrested and demanded a CBI probe into. The opposition parties, including the AIADMK and BJP also demanded a CBI probe and also met Governor R N Ravi and petitioned him in this regard. The CB-CID police, which was probing the case, have so far arrested 11 people in connection with the murder. All the 11 accused were sent to five days police custody for interrogation on July 11 by a Magistrate Court on a petitioned filed by the CB-CID...////...