The city police shot dead a 28-year-old man, who was arrested for hacking a constable, near the Central Polytechnic College campus at Taramani in Chennai on Tuesday.
Police, who have already arrested six men involved in the attack, killed Anandan in an encounter at CPT campus in Taramani late on Tuesday night.
A resident of BV Naicken Street in Triplicane, Anandan has 12 cases, including two attempt to murder cases, against him.
According to the police, though most members of the gang that attacked Rajavelu were arrested on Monday, Anandan and his aide Arul, the two prime accused, were absconding.
On Tuesday evening, the police received information that Anandan was hiding in Sholinganallur. A special team, headed by Mylapore DC P Saravanan, was formed. The team also included Kotturpuram AC K N Sudarshan.
According to police, they acted in self-defence when Anandan pulled out a knife and started attacking Sub-Inspector S Ilayaraja. Sources said it was Assistant Commissioner Sudharsan, who fired the shot, on seeing Anandan attacking the SI.
His body was then taken to Government Royapettah Hospital for autopsy.
Police constable Rajavelu, 35, on night patrol duty, rushed after a distress call landed at the city police control room on Monday night. On noticing at least 10 people assembled at a spot, consuming liquor in public place and creating ruckus, Rajavelu questioned them and advised them to disperse.
They, however, attacked him with sickles and knives. Rajavelu suffered severe injuries on his head and face, requiring more than 30 stitches.