The NYPD released new surveillance video showing the moments gunfire erupted in Brownsville, injuring four people Sunday night.

A 16-year-old is among four people who were injured in a quadruple shooting in front of 265 Livonia Ave., according to police. In the video, someone is seen running with two others behind them. Then, the person in front turns and starts shooting.

Police are not only trying to find the person who pulled the trigger, but also trying to figure out why it appears they were being chased.

Police say a 59-year-old and 34-year-old had graze wounds. A 24-year-old was shot in the abdomen and the 16-year-old was shot in the head. They are all expected to survive.

Lateeka Richardson, the mother of the 16-year-old victim Jeffrey Thomas, told News 12 Thomas was an innocent bystander and had just gone to the store to get soda, but never made it home.

Police are continuing their search for the shooter and more clarity. Anyone with information is asked to call police at 1-800-577-TIPS.