CNN aired the footage Monday during an interview with eyewitness Piaget Crenshaw, who said she recorded it following the Aug. 9 shooting.
According to Crenshaw, the footage shows Michael Brown's body lying in the middle of the street as Wilson stood over him speaking to another officer.
"God bless his soul, the police shot this boy outside my apartment," Crenshaw could be heard saying on the video while crying. The video also picked up the voices of spectators near the crime scene.
In another portion of the video, a man Crenshaw identified as Wilson could be seen alone, pacing near Brown's body.
Crenshaw, one of the first eyewitnesses to come forward in the wake of the shooting, said that her attorney initially advised her to hold back the video for "her own personal safety," and also because Wilson's identity was not revealed until Friday.
"We wanted to kind of put this name with a face," Crenshaw explained.
Narrating the video to CNN's Michaela Pereira, Crenshaw described her account of the scene.
"What we're looking at is officer Darren Wilson to the right," she said. "He's just looking over the body, just looking baffled and bewildered of sorts, like trying to explain to the officer, 'What have I just done?'"
"And then we get this picture of him pacing back and forth, just like in disbelief," she said. "It's like he understands that he just shot this boy in the face and this boy was unarmed."
Watch the video segment below. (Warning: The clip contains some graphic imagery.)