A key accused in the murder of BSP Tamil Nadu chief K Armstrong was shot dead, police said, adding that he allegedly opened fire at them and attempted to flee from their custody. Opposition politicians raised questions about the police’s version of events that led to the killing of K Thiruvengadam. According to police, when Thiruvengadam was taken to Manali as part of the investigation, he escaped from their custody after pushing away the policemen on escort duty. Though the police personnel tried to apprehend Thiruvengadam, he fled, the police said. Eventually the sleuths spotted him at a nearby locality. When they tried to arrest him, the accused allegedly opened fire at the police using his unlicensed pistol. For self-defence, a police inspector shot Thiruvengadam, the police said.