The killing, in December, took place in daylight in a drugstore in a small western German town, shocking the nation and emerging as a rallying cry for the far right and others opposed to Chancellor Angela Merkel’s open-door migration policies of recent years.

On Monday, in the drugstore case, a court convicted a man identified by authorities as Abdul D. of plunging a kitchen knife with an 8-inch blade into the heart of his ex-girlfriend. In the days after the attack, hundreds of people flooded Kandel, a town near the French border.

Prosecutors argued that the young asylum-seeker had been jealous after the victim, who in keeping with German privacy law has been identified only as Mia V., broke up with him several weeks earlier.

Twelve days before she was stabbed, she filed a report with police accusing the defendant of insulting and threatening her, and her father then reported him to authorities two days before her death.

The mayor of Kandel, Volker Poss, said right-wing groups were organizing demonstrations in the town for later Monday, to protest what they saw as an overly lenient sentence for the killing.

The court handled the case as a juvenile offense, because Abdul had claimed he was 15 at the time of the killing. Although an expert analysis had suggested he was older than 17, and possibly as old as 20, authorities decided not to try him as an adult. That meant the maximum penalty was 10 years in prison.

Migrants younger than 18 are treated as juveniles in Germany, meaning they are afforded better benefits. This has led many young men to enter the country without documents and lie about their age.

This article originally appeared in The New York Times.

Melissa Eddy and Richard Pérez-Peña © 2018 The New York Times