NEW DELHI: Alcohol-fuelled revelry at Burari, CCTV footage from Red Fort and a suspicious man with a gunshot wound in hospital - these were the clues that helped police crack the case of robbery that took place in the Pragati Maidan tunnel on Sunday.Under fire for the crumbling law and order situation in the city from all quarters, it was a race against time for the cops.

The Crime Branch, which made five arrests in the case till Tuesday night, joined the probe only on Monday as the case was initially handled by the local police.

However, after the CCTV footage of the road heist surfaced, Crime Branch chief Ravindra Yadav was tasked to crack the case at the earliest.

And Yadav's team didn't disappoint.Piecing together what leads they had, the Crime Branch team managed to solve the puzzle swiftly enough to fend off criticism.

"The accused were in the process of escaping to distant places after switching off their phones," said special commissioner of police Yadav.

"Nabbing them in time saved us enormous manpower and resources that would have been required to trace them later."The investigation in this case, the cops agreed, demonstrated how hum-int (human intelligence) could supplement tech-int (technical intelligence) in key investigations.The Crime Branch started off by activating their informers about any recent movement that could be connected with the tunnel.

The investigators also started scanning the footage of CCTV cameras in the area.The first lead came when a man named Vishal reported being shot in his stomach.

He claimed to have been standing at Burari Chowk when someone shot him and fled.

When the cops probed his complaint, things didn't seem to add up.

There were no corroborating movements or other indications on footage from CCTV cameras.02:28Caught on camera: Daring daylight robbery at gunpoint in Delhi's Pragati Maidan tunnelThe man, when cross examined at length, finally disclosed that he was part of a gang that had been planning to rob cash collection agents and had acquired weapons for the purpose.

Vishal further revealed that he had accidentally fired from the pistol, which was to be used in crime, and was injured as the bullet ricocheted and hit him.

The tempo driver also revealed the identities of his associates.The Crime Branch received another crucial tip, a hum-int input on Monday, about a party at a banquet hall two days before the robbery and another after the crime.

Apparently, the criminals reached the house of their mastermind, Usman, in Burari after the robbery to divide the booty.

A booze party followed and from this came the tip for the cops.The third lead was a CCTV video clip from the spot near Red Fort where the two cash agents ferrying the money to Gurgaon got off a cycle-rickshaw to board an Ola cab.

The analysis of this footage revealed two spotters, later identified as Usman and Sumit, standing nearby and talking on the phone.

The cops started looking for these men in the nearby localities.The cops mounted technical surveillance and sought the dump cell phone data, which consists of all active mobile numbers of the area.

The investigators needed the data from two spots, Red Fort and the Pragati Maidan tunnel.

The data so obtained would have numbered at least 10,000 phones and the cops had to find the common numbers active at these two places.

It was like trying to find a needle in a haystack.But things fell into place, and the Crime Branch conducted raids in Delhi, UP and Haryana before nabbing two of the suspects.

The local police also managed to arrest two other suspects simultaneously.Dependra Pathak, special commissioner (law and order), said, "The investigation and efforts underlined the operational capabilities and professionalism of Delhi Police, making it clear that the culprits behind any crime, however smart, would be brought to justice and put behind bars."Special CP Yadav added, "The quick solving of the case was an example of excellent coordination and synergy between the teams of the district police and the Crime Branch."The police teams are now on the lookout for the rest of the suspects who are believed to be hiding in Haryana, Rajasthan and UP.

Raids are being conducted at over a dozen places, sources said.