CHICAGO — Rahm Emanuel sought for months to keep the public from seeing a video that shows a white police officer shooting a black teenager 16 times.

Now, a week after the video’s release, the Chicago mayor has fired the police superintendent, created a task force for police accountability and expanded the use of body cameras.

But Emanuel’s effort to keep the video secret and long wait to take action at the police department have stirred deep skepticism among those protesting 17-year-old Laquan McDonald’s death. Many activists are especially incensed by the fact that the video of the October 2014 shooting first surfaced during a re-election campaign, when the mayor was seeking African-American votes.

“In our community, everyone is saying it (the video) was not released because of the election,” said Corey Brooks, a prominent black minister.