Martin had bought ingredients that can be used for natural highs and was standing on a street corner (where there had been multiple burglaries around the time), in the rain looking suspicious (probably waiting for someone), Zimmerman confronted him and was attacked and yes had his head smashed onto the concrete. He may have been on a power trip, but Martin was a lowlife thug. They both sound like thugs and scum. The only problem is how the media distorted the reality for their own means which has resulted in more trouble. If people had any brain cells, they'd be rioting outside CNN studios etc, but instead their anger gets directed at a lone 'white' thug.