A murder accused, who was out on bail, was shot dead allegedly by his stepbrother in suburban Kurla on Tuesday, a police official said.
Janu Pawar alias Billa was on Halav bridge in Kurla area in the morning when Vinod Pawar (30) allegedly fired two rounds at him, he said.
He was rushed to the civic-run Sion Hospital where doctors declared him dead before admission, he said.
Police first detained and then arrested the deceased's stepbrother Vinod Pawar for the crime.
Efforts are on to nab an aide of Vinod Pawar who fled from the area following the incident, police added.
"The killing was possibly the fallout of a domestic tussle. We have registered a murder case and are probing further," the official said.
The deceased was earlier granted bail in a murder case, the official said, adding he had several criminal cases registered against his name in Mumbai.