Residents in Lancaster, Pennsylvania gathered outside the city's police department on Sunday (September 13) to protest against an officer-involved shooting.
According to reports, officers responded to a report of a domestic dispute, then the officer shot a man who was believed to have a knife.
Police did not disclose the details of what led to the shooting.
The victim was identified as Ricardo Munoz and pronounced dead at the scene.
The incident was caught on a body cam and an officer has been placed on administrative leave.
Lancaster District Attorney tweeted: "We have reviewed body cam footage which shows man ran at @LancasterPolice while brandishing a knife above his head.
Our investigation is ongoing."