Mr. Garner’s last words, “I can’t breathe,” galvanized the Black Lives Matter movement.

The New York City police officer whose chokehold led to Eric Garner’s death in 2014 was fired from the Police Department and stripped of his pension benefits on Monday, ending a bitter battle that had cast a shadow over the nation’s largest police force.

Commissioner James P. O’Neill’s decision to dismiss the officer, Daniel Pantaleo, came five years after Mr.