The hardest part of the investigation was eliminating the long list of suspects and narrowing down on the accused, said K.G. Simon. The list of suspects included Thampi, who was a stranger to Mohanan and was spotted attending the marriage function of the latter’s son. Another suspect was Martin, whose slip of tongue did him in. During a drinking session in the Middle East where he worked, he claimed he was the killer. The police brought him to Kerala and questioned him. However, his involvement was ruled out. Sadanandan, Mohanan’s assistant and Anwar, driver of one of his trucks, were also suspected and interrogated in detail during the probe. The Crime Branch team also checked the possibility of Rafi, another spirit smuggler from Thiruvananthapuram, getting involved as Mohanan had given him much trouble.

There were news reports that Satish Kalia, one of the sharp-shooters in the Chotta Rajan gang, was hired for the crime. However, police ruled out the possibility after finding out that he was in prison.

The police had interrogated nearly 110 witnesses in the case.