CHICAGO — On an autumn night in 2014, a black teenager named Laquan McDonald was shot dead by a Chicago police officer. Nearly five years later, on Thursday, a city oversight board voted to fire four other officers accused of covering up the circumstances of Laquan’s death.

The process, which could extend further if the officers choose to challenge their firings in court, was a reminder of how long it often takes to reach resolutions in cases where people die in encounters involving the police. Earlier this week, in New York City, federal prosecutors said they would not seek civil rights charges against Officer Daniel Pantaleo, who placed Eric Garner in a chokehold that led to Mr. Garner’s death five years ago.

In Chicago, Laquan McDonald’s death touched off years of political upheaval and led to promises to overhaul the Police Department. Yet even with intense public interest, the legal and disciplinary processes played out slowly.

Last October, almost four years after the shooting, Jason Van Dyke was convicted of murder for firing 16 shots into Laquan. In January, three other officers were acquitted on criminal charges that they had covered up the shooting. And finally, on Thursday, the Chicago Police Board voted to fire four other officers for their actions after the shooting: Sgt. Stephen Franko and Officers Ricardo Viramontes, Janet Mondragon and Daphne Sebastian.