Dozens of people gathered outside the Bedford-Stuyvesant home of Tayloni Mazyck.
The 11-year-old girl is now paralyed after a bullet hit her in the neck on Friday.
Nearly half of the 25 shootings in the city over the weekend were in Brooklyn.
Brooklyn District Attorney Charles Hynes urged residents to demand change.
17-year-old Kane Cooper was arrested and charged with shooting Tayloni.
Hynes says Cooper could get up to 65 years in prison for the charges.