George Zimmerman acted in self defense against Trayvon Martin.

At the outset, let's establish that the central question herein, is not whether George Zimmerman acted in self defense, but whether or not George Zimmerman's reckless and unwarranted aggressive actions were in fact what caused and provoked the incident to begin with. If George Zimmerman, a failed wannabe rent-a-cop, had not needlessly taken the law into his own hands, a teenager who was out to do nothing more than buy a bag of skittles and a bottle of iced tea would in fact be alive today. The idea that one can start a fight and then when losing that same fight respond with deadly force is both ludicrous and dangerous. So now that we understand what the real issue is here, let us begin to respond to your points: "1. Did George Zimmerman have reasonable cause to investigate?" - The last I checked no one hired George Zimmerman as an "investigator" nor is there any evidence to support the concept that he was at all qualified to conduct any sort of "investigation". "Reasonable cause" for investigation is a concept that applies to law enforcement's right to obtain a search warrant, a right that will require trained law enforcement to actually go to court to show "reasonable cause" to actually obtain such a warrant. If you are asking whether or not it was "reasonable" for a self appointed neighborhood watchman to contact the police when he saw someone unfamiliar and perhaps suspicious to him in the neighborhood? Of course that would be. In fact it would be "reasonable" for Mr. Zimmerman to keep an eye on such a person and watch him from a distance while waiting for the police to arrive. However, it is and was patently "unreasonable" for Mr. Zimmerman to take this matter into his own hands and confront the person he was watching with a gun, particularly after law enforcement expressly told him not to. If we want to ask about "reasonableness" I will ask the question whether or not it is reasonable for a 17 year old male minding his own business to protect himself when confronted for no reason whatsoever while he is out on a simple stroll home from a convenience store. To address your second point "Did George Zimmerman break any laws when carrying a gun?" - Well carrying the gun didn't break any laws, but using it recklessly to murder someone did. Point 3. "Who was the man crying for help" No one except the 2 involved will ever know this for sure. There are people testifying on both sides. The scientific experts that were not allowed in the trial actually stated that it was most likely a teenage boy. It is highly possible that both sides were crying for help at some point. It really doesn't matter. There was a confrontation. It was unnecessary. It was started by Zimmerman and Trayvon Martin was killed. Point 4: "What do the injuries say?" - They say that Trayvon is dead and Zimmerman had some MINOR bruises. They say that two guys were in a fistfight and one (who started the confrontation) elected to use deadly force. The people who have allowed this to become a debate about whether or not Zimmerman was acting in self defense have lost sight of the case. Zimmerman targeted what was in his own words one of those "a--holes" who "always get away" and took it on himself to handle one of those (again in Zimmerman's words) "f--cking punks". It is unfortunate that the big man Zimmerman was not as tough as he pretended to be when he confronted an innocent kid. It is tragic that anyone thinks it is justifiable for him to shoot that young man.