On Camera: US Cop Fatally Shoots Man After Mistaking A Marker Pen For A Knife

The Denver police chief, Ron Thomas, called the shooting a "tremendous tragedy," but defended the officer's decision to fire two fatal shots.

A police officer in the United States fatally shot a man who was holding a marker pen, which the cop mistakenly believed was a knife. 

The Denver Police Department on Monday released a graphic body camera footage of the incident which took place on August 5. The clip shows an officer firing two shots at Brandon Cole, 36, as he ran towards the cop holding a marker, not a knife, authorities confirmed. 

"This is a tremendous tragedy," Denver Police Chief Ron Thomas said about the shooting, which is still being investigated, CBS News reported.