BERLIN—A German court on Wednesday sentenced a Russian man to life in prison for shooting dead a former Chechen rebel leader in Berlin at the behest of Moscow, in a case that has further frayed already tense relations between Germany and Russia.

The Berlin court found Vadim Krasikov guilty of gunning down Georgian national Zelimkhan Khangoshvili in a park in broad daylight in August 2019. The court said that the killing was ordered by Russian authorities.