Kolkata, May 10 : Even 72 hours after the murder of Chandranath Rath, personal assistant to Chief Minister Suvendu Adhikari, the assailants remain at large, with police yet to make any arrests.

Investigators say their biggest challenge is tracking the attackers' escape route due to a lack of usable CCTV footage. Several cameras along the route adjacent to Doharia-Mathpara in Madhyamgram, through which the miscreants are believed to have fled, have been out of order for a long time, a senior police officer said on Sunday.

The shooting took place on Wednesday night in the Doharia area of Madhyamgram in North 24 Parganas district, where the assailants stopped Rathâ??s car mid-road before opening fire. After the attack, the attackers are believed to have fled the scene on motorbikes via an alley road towards Peyara Bagan. A search is underway along that route, but the absence of effective CCTV coverage at key locations has hampered the investigation.

Police investigations have revealed that many CCTV cameras in the area have been non-functional for a long time, while some installed on light poles were positioned incorrectly. As a result, no clear visuals of the attackersâ?? movements are available. CCTV cameras at roadside shops have also yielded no clues, as most establishments were closed at the time of the incident.

A section of investigators believes the assailants deliberately waited for darkness to fall so that faces and number plates would not be clearly captured as they sped away on their bikes, the officer said.

Meanwhile, a red car has emerged as a new mystery in the case. CCTV footage shows the vehicle following Rathâ??s Scorpio from Birati intersection to Jessore Road and remaining close behind even after entering the Doharia area. Investigators suspect the car may have been tailing Rath from the start, and a vigorous search is underway to trace it.

A special investigation team has been formed to probe the case, which police believe was executed in a well-planned manner.

/IANS