Uttar Pradesh police is relying heavily on 500 pages of purported electronic evidence included in the 1700 pages long charge-sheet filed with the hope to mount a foolproof case against slain Kanpur gangster Vikas Dubey and his aides, accused of involvement in a planned ambush of a police raid party on July 2.

The electronic evidence in the charge-sheet contains the call details report (CDR) of all the 36 accused in the case.

The investigators built a matrix analysing the numbers and locations to show that the accused were at one place and in touch with each other. The police investigation has placed the numbers in chronological order to establish a step by step sequence of events, which led to brutal killings of eight policemen.

For example, the first CDR placed in the charge-sheet is of sub-inspector KK Sharma, establishing that he spoke 13 times with Vikas Dubey and his men. It places emphasis on the conversation Sharma had at 11.44 pm on July 2 with Ram Singh, one of the accused. The investigation claims it was during this conversation, which took place 10 minutes before the FIR was registered and the police party left for the gangster’s village, that the details related with the raid were leaked.

This follows the CDR of Vikas Dubey, which establishes that he called police constable Rajeev Singh of Chaubeypur police station and threatened to kill the police team coming to raid his house. In corresponding calls, he spoke to his aides Amar Dubey, Prem Prakash Pandey and Prabhat Mishra, all of whom were killed in various encounters with the police.

Other CDRs of accused were mentioned in the charge-sheet to establish that they called each other in Bikru to coordinate the ambush on the police team.

The call records of four women accused in the case have been attached separately in the charge-sheet. Officials said Manu Pandey, whose audio clips confirmed the involvement of women in the attack, according to police, hadn’t been given a clean chit either.

She would be made an accused in the supplementary charge sheet, said an official.

An official said the police tried to explain through these records how the attack was planned, how the accused remained in touch with each other, how they escaped, the routes they took after killing the policemen and how the police officers accused in the case were in touch with some accused and helped them.

District government counsel (DGC) Kanpur Dehat, Prashant Mishra, said the charge-sheet was comprehensive and enough evidence was on record to secure conviction of the accused.

But Shivakant Dixit, a lawyer representing a minor accused, Khushi Dubey, said the charge-sheet was riddled with loopholes. There were 500 pages of CDR but how the police would establish what conversation took place between the accused, he asked.