Police were able to zero in on the bearded man, clad in a checked shirt and dark blue jeans — as seen on the CCTV footage obtained from a nationalised bank on Rajiv Gandhi Salai in Perungudi — after meticulous examination of over 1,000 footages gathered from 40 branches of various banks and their ATM kiosks on Old Mahabalipuram Road, Besant Nagar and Tambaram.

On January 23, an armed robbery took place at the Bank of Baroda, Perungudi branch, where four men fled with over Rs.19 lakh after holding the staff and customers hostage. The gang struck at the Indian Overseas Bank, Keelkattalai Branch in less than a month and decamped with Rs.14 lakh.

Gang struck on Monday

In both the cases, the police suspect, the gang struck on a Monday in the hope of finding more cash on the teller since it is the first business day of the week. They were clearly not interested in the locker which had large sums of money and a lot of gold jewellery, police sources said.

Following the Perungudi incident, special police teams formed gathered CCTV footages for the month of December and January from all the bank branches and ATMs on the OMR.

According to sources, computers were set up inside the Perungudi branch of Bank of Baroda and the footages were played and examined. Bank staff and some customers who had witnessed the robbery unfold were made to watch the footages for a few days.

Investigators struck gold when a witness, who was viewing the footages, identified a bearded man moving around inside a bank in Perungudi as the person who held the Bank of Baroda manager at gunpoint.

The footage was screened for other witnesses including the IOB officials who ascertained that the man had led the gang during Monday's robbery, the sources added.

Investigators are in the process of examining the remaining footages in an attempt to hit upon possible images of other members from the gang of robbers.