A threat message to a CID officer written on the wall of a pulse mill where a labourer was found murdered on Wednesday gave away the killer, police said.

Cops matched the writing of the message, “CID officer Raj Sadhan…. Agar zyada chalaki karoge toe khud fas jaoge”, with that of the jottings in a notebook, the police said.

Suman Sheikh, 29, who is a labourer at the mill in Ultadanga has been arrested in connection with the murder. Sheikh, who hails from Birbhum, could not flee the city because of the lockdown on two consecutive days and he spent two nights inside Deshapriya Park, the police said.
He was picked up from the park on Friday morning.

“He wanted to warn cops to stay away from him. He had made up the CID officer’s name,” an investigator said. “There were two writings on the wall. One was about the ‘CID officer’ and the other about another labourer, Kanbali. Initially, we had detained Kanbali and questioned him. But we realised the culprit was trying to divert us.”

Rakesh Shaw, 30, was found dead with multiple injuries inside the mill on Wednesday.

Kanbali had told cops that Sheikh used to jot his songs down in a notebook. “We got the handwriting sample from the notebook... prima facie it matches with the writing on the wall. He has confessed to the crime,” an officer said.

Shaw and Sheikh had an old quarrel and on Tuesday night, Sheikh had tried to take some money out of Shaw’s pocket, the police said. He woke up and resisted and got killed with a knife.