THIRUVANANTHAPURAM: Technology has come to the forefront in crime investigation today. The mobile phones provide vital clues about the perpetrators. But till a few years ago, the modes of investigations were different. The police would collect witness statements, analyse possible motives, verify call details of nearby public telephone booths and get information from bus stands and railway stations. But the advent of mobile phones has changed the scenario. The police now verify the call records of victims or suspects and analyse the calls connected through the phone towers near the crime spot. This was how the police cracked the Paul Muthoot George murder and Jisha murder cases.
However, in well-planned crimes mobile phones could be used by the culprits to mislead the investigation and claim alibi. Hence, the police have to scientifically analyse the mobile phone data, which could take weeks or months, and collect corroborative evidence. The state police have mobile forensic lab equipped with mobile forensic tool for call data records analysis. In the Jisha murder case, an in-depth analysis of mobile phone call details from nearby mobile phone towers helped the police zero in on the accused. About 25 lakh mobile calls were analysed with various parameters. Finally it was found that one mobile phone that was being used in the locality frequently had stopped the calls after the murder.
“The mobile phone has made it easier for the police to get leads in crimes that leave no eyewitness. But the crucial part is the analysis of the call details from among thousands of details. Hence, the intelligence of the investigators is very crucial,” said former state police chief Jacob Punnose. “The Paul Muthoot George murder was not pre-planned, but it followed a road rage. Hence, the information from mobile phone towers helped track the culprits,” said a police officer who was part of the investigation. According to noted cyber crime investigator Dhanya Menon, the intuition and experience of investigating officers are vital in picking up crucial evidence from lakhs of call detail records.
“The forensic experts are being given vital inputs for analysis by the investigators,” she said. Mobile phones are sometimes used to mislead the probes. In the hand-chopping case of Thodupuzha Newman College professor T.J. Joseph, the culprits used a phone and connection taken using fake identity during the execution of the crime. Even then the police cracked the gang. “The mobile phone connections taken using fake identity cards are used for crimes occasionally. Stringent measures need to be initiated to prevent such instances,” said Mr Punnoose.
The evidence for the motive is important to establish a crime before a court of law. Phone call records are not enough to prove the conspiracies. “Just because a communication took place between two mobile phones, it cannot be established that it was between the owners of those two phones. To establish that, there should be sufficient corroborative evidence,” said a senior police officer. A probe into the larger conspiracy behind the murder of RMP leader T.P. Chandrasekharan also reportedly led to some CPM top leaders on the basis of call detail records. But the investigation got stalled midway.
The duration of mobile forensic analysis in a case would depend upon the level of information required by the police. “If only basic details like location of a mobile phone is required, it could be done in no time. In case an in-depth analysis of lakhs of calls is required, it may extend up to an year,” said Dhanya. In the ongoing probe into the actor abduction and rape case, the police got vital leads from mobile phone calls. There were unconfirmed reports that in an undercover operation, the police facilitated the use of mobile phone by the accused Sunil Kumar alias Pulsar Suni in the prison cell to extract more information on the conspiracy.
How the police cracked them
Jisha murder case: Accused was traced following in-depth analysis of about 25 lakh mobile phone call details from nearby mobile towers, known as the tower dump.
Paul Muthoot murder case: With no record on pre-planning for the murder or previous rivalry between the victim and the accused, the police got vital leads through analysis of call details of mobile phone towers in the locality.
Bar bribery case against K. M. Mani: Though the vigilance investigating officer concluded that there were evidences on bar owners handing over bribe to former Finance Minister K. M. Mani, vigilance higher-up disproved it through in-depth analysis of mobile phone locations of those allegedly involved in the deal.
Hand-chopping case: The gang that chopped the hand of Thodupuzha Newman College professor T. J. Joseph used a new mobile phone bought using a fake identity card before executing the crime. But the police could unfold the operation.
TPC murder conspiracy: A probe into the larger conspiracy behind the murder of RMP leader T. P. Chandrasekharan reportedly led to some CPM leaders on the basis of their call records. Since the call records were old past a year by the time the investigation was initiated, those need to be certified by the centre for authenticity. The probe got stalled at that stage.
