The Special Investigation Team probing the October 17 stampede at the Chor Bagan Durga Puja pandal that killed 19 people focused on its narrow seven-foot exit point and dim lighting.
Police forensic teams deployed drones and created 3D maps of the site, where grieving families alleged that an emergency gate used for VIP movement was locked during the surge.
An eighth accused, Sanjib Raha, was arrested in Nadia for allegedly making loudspeaker announcements that triggered panic about the pandal collapsing.