Detroit police released video this week of a brutal knockout attack during an attempted robbery.The suspects knocked an elderly man out during an attempted robbery. The second suspect hit the man after he fell unconscious to the ground.The suspects knocked an elderly man out during an attempted robbery. The second suspect hit the man after he fell unconscious to the ground. This was so brutal–" ideo from a surveillance camera in a Detroit liquor store shows the brutal attack of a 64-year-old man during an attempted robbery that happened last weekend. Police released the video Friday with the hope that...