It took more than a year from the night a white Chicago police officer fatally shot a black teenager until the city's top prosecutor announced murder charges against the patrolman.

The long wait has provoked sharp criticism of Cook County State's Attorney Anita Alvarez. Next it could cost Alvarez her job.

The first woman and first Hispanic to serve in the post, Alvarez was facing a tough 2016 re-election even before last week's release of the footage of officer Jason Van Dyke shooting Laquan McDonald in October 2014.

Since then, protesters have accused her of trying to cover up the crime and filing charges only because a judge had ordered the video's release. Key supporters have said they'll no longer back her.

Alvarez says she won't resign.