Police Commissioner James O'Neill and Mayor Bill de Blasio presided over Thursday's ceremony, which took place 32 years to the day after McDonald was shot three times by a 15-year-old boy while investigating a bicycle robbery in the park.
McDonald survived, but the shooting left him paralyzed from the neck down and needing a ventilator to breathe.
Eight months later, McDonald forgave the teen and then traveled the world, inspiring others with speeches on faith and forgiveness.
McDonald died on January 10, 2017, at age 59 after suffering a heart attack.
McDonald's wife and son say they hope the plague serves as a reminder of his legacy.
"If a man who was shot by a 15-year-old kid when he did nothing, but just try to talk to him - can live a life of love and compassion, I think we all can do that and we all can sit down and talk to each other," said McDonald's son, Conor, who followed in his father's footsteps and is now a sergeant in the NYPD.
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