ASI Shaktipada Hazra found three strangers standing in front of his house, leaning against two motocycles at around 1 am on Friday, the police said.
When Hazra asked his son to inform the Bally police station after the three men did not reveal their identity, the youths fired at him and escaped from the spot, Deputy Commissioner (Headquarters), Vineet Kumar Goyal said.
Hazra was sent to the Calcutta Medical College and Hospital.
The bullet has been extracted from his body and his condition is stated to be stable now.