Washington, Dec 8 (IANS): A US policeman has been sentenced to 20 years in prison for killing an unarmed African-American man in 2015, according to the Department of Justice.

The ruling and severity of Thursday's sentence was unusual for the US where officers being convicted or charged with crimes for using fatal force is rare, reports Efe news.

The incident occurred in South Carolina in April 2015 when Slager, a former North Charleston Police Department officer, stopped Walter Scott's vehicle after observing its brake light was broken.

After stopping the car, Scott fled on foot away from Slager towards a vacant lot when the officer shot him five times in the back.

A passer-by recorded the scene on phone which led the judge to consider the death as a second-degree homicide.

Scott's death came as police forces across the US were facing criticism and were under increased public scrutiny due to the deaths of several black people, particularly men, at the hands of the police.

The case that triggered widespread massive condemnation was the death of Michael Brown in Ferguson, Missouri, in 2014, a shooting that sparked violent protests and revived racial tensions in the country.

In Scott's case, a video of the incident taken by witnesses was widely shared, leading to his arrest days later.

In May 2017, Slager pleaded guilty to violating Scott's civil rights.

The deceased's family reached a financial settlement worth $6.5 million with the North Charleston municipality.