The Supreme Court has spared gallows for a police ‘‘black commando’’ constable by awarding him life sentence after upholding his conviction for killing three of his colleagues for making adverse remarks against him. The Court said the death penalty was not just punishment as the crime was committed in a ‘‘perturbed and imbalanced’’ state.Constable Gyasuddin Khan, a black cat commando, while posted in Bihar in 1996 shot three of his colleagues after being rebuked twice by a senior. The Court felt that life imprisonment was the right punishment considering his mental state.