CHICAGO — Three longtime police officers were charged on Tuesday in connection with the death of Laquan McDonald, the black teenager whose fatal shooting in 2014 at the hands of a white Chicago officer ignited intense scrutiny over police conduct and transparency.

Unlike the officers accused in a series of police shooting trials that have unfolded around the country in recent weeks, those charged here did not fire their weapons. Their crimes, prosecutors said, stemmed from their actions after the shooting. The three officers, two of whom have since left the force, are accused of covering up for Jason Van Dyke, the police officer who fired the lethal shots that night, in an effort to protect him from being investigated and charged, court documents show.

The officers were indicted on state felony counts of conspiracy, official misconduct and obstruction of justice. Among the claims were that they provided false reports about how Mr. McDonald, 17, behaved when he encountered Officer Van Dyke on a Southwest Side street one evening in October 2014; and that the officers went so far as to work together to sidestep interviewing at least three witnesses whose accounts of events would have conflicted with the official police version.

“These defendants lied about what occurred during a police-involved shooting in order to prevent independent criminal investigators from learning the truth,” said Patricia Brown Holmes, a special prosecutor who announced the new charges. “The indictment makes clear that it is unacceptable to obey an unofficial code of silence.”