BERLIN (AP) — A German man was convicted of murder and given a life sentence on Tuesday for fatally shooting a young gas station clerk following a dispute over face masks.

The killing in the western town of Idar-Oberstein on Sept. 18 last year shocked the country. The 50-year-old defendant was convicted by a state court in Bad Kreuznach, German news agency dpa reported.

Authorities have said the man told officers he acted “out of anger” after being refused service by the 20-year-old clerk for not wearing a mask while trying to buy beer at the gas station. A requirement to wear masks in stores was among the measures in place in Germany at the time to stop the spread of COVID-19.

Police said the suspect, a German citizen named in local media as Mario N., left the gas station after the dispute but returned a half-hour later and shot the clerk in the head.

He initially fled the scene but turned himself in to police after a large-scale manhunt was launched.

The suspect was also convicted of illegal weapons possession because he didn't have a license for the gun used in the killing.