The Special Investigation Team (SIT) probing into the murder of Chandranath Rath, a close aide of BJP leader Suvendu Adhikari who is now the Chief Minister, has found that the assailants had prior information about Rath’s position inside the vehicle while he was returning home on Wednesday night, police sources said on Saturday.Three people have been detained in connection with the killing and are being questioned, police said, adding that no arrests have been made so far.Investigators suspect that bike-borne gunmen brought in from outside West Bengal executed the attack with precise planning, taking barely 45 to 50 seconds to shoot Rath dead in his car on a busy road in Madhyamgram in North 24 Parganas district.“It appears that the shooters knew exactly where the target was seated inside the vehicle. The execution was swift and professionally coordinated,” a senior SIT officer said.According to investigators, apart from a silver-coloured car that blocked Rath’s vehicle near Doharia crossing in Madhyamgram, the killers used a red vehicle to flee.Police said the attackers also used a motorcycle to run away.“CCTV footage collected from the area indicates the presence of another vehicle trailing the silver car. We are examining all movement patterns and escape routes,” the officer said.The SIT believes at least eight people were involved in the operation, including local criminal associates who provided logistical support to the shooters.Investigators recovered one motorcycle near the No. 11 rail gate area in Barasat on Friday morning. Another motorcycle had earlier been found near the crime scene.Preliminary findings suggest that the red car and the motorcycles had been stolen earlier, another source in the police said.Two police teams have been sent to Uttar Pradesh and Bihar as investigators suspect the sharpshooters were brought from those states, he said.