Ferguson, Mo. Police Chief Thomas Jackson on Friday identified Officer Darren Wilson as the cop who fatally shot unarmed 18-year-old Michael Brown last weekend.

Jackson said Wilson had been with the force for six years and had no prior disciplinary action taken against him.

Wilson was responding to a report of a “strong-arm robbery” when he encountered Brown, Jackson said, and the officer was treated Saturday for injuries he sustained in the incident.

This post has been updated.