Dadar Railway Protection Force (RPF) Constable BS Tayade is monitoring CCTV footage at Sion Railway Station around 1.55 pm on November 17, when he notices something odd. A man, Ashok Sayappa Mangali, 26. who is just about to reach the ticket window, leaves it and goes to the back of another queue. Cops later find out he was scouting for a victim. Illustrations: Ravi Jadhav