3 policemen accused of cover-up stand trial in Chicago

Three Chicago police officers went on trial on Tuesday for alleged cover-up in the controversial killing of a black teenager by their colleague four years ago.

Jason Van Dyke, the fellow officer, was already found guilty of second-degree murder last month in fatally shooting 17-year-old Laquan McDonald in 2014.

The three Chicago police officers have been accused of falsifying reports to protect Van Dyke. They now face charges of conspiracy, obstructing justice and official misconduct.

McDonald reportedly broke into a truck on the night of Oct. 20, 2014 and Van Dyke was one of police officers dispatched to the scene. McDonald carried a knife but walked away from police when Van Dyke fired 16 shots into the teenager, the police car's dashcam video showed.

However, before the release of the police video, the three accused officers allegedly made false statements during the initial investigation, exaggerating the aggressiveness of the black teenager in an attempt to shield their colleague.

The 2014 incident triggered racial tension in Chicago, the third biggest city in the United States with a large African American population.

Community and faith leaders, speaking ahead of Tuesday's trial, called for an end to nepotism in the police force, stricter judicial supervision and urged to rebuild relationship between the police and local communities.