If anyone read the article carefully they would see that one of four men was seen shooting three men on a street corner. Despite the fact that here in Atlanta police officers have been proven to lie about what they witness, I will go with the assumption that what the surveillance officers saw was accurate and true.

"Police said they saw four men get out of a vehicle and walk to the corner. One reportedly fired upon three men who were standing on the corner, and then took off running. The other three men, his companions, were said to have jumped back in the car and sped off." -- taken from the article above

Even with that, the only thing the other men were seen to have done, according to this article, is leaving the scene of a crime. Surely, a beat down like they appear to have received was excessive for that offense.