Zimmerman told police he shot Martin in self-defense, but that doesn't sit well with Martin's parents.  "When you add it up, it just doesn't even make sense," said Ben Crump, the Martin family's attorney. "Trayvon Martin, a kid, has a bag of Skittles. [Zimmerman] had a 9mm gun. Trayvon Martin didn't approach George Zimmerman, George Zimmerman approached Trayvon Martin. So how can he now assert self defense?"  Police say a gunshot can be heard on the 911 calls recorded that night.  Sanford police said Monday the calls will not be made public until the investigation is complete, but the Martin family is pushing for the tapes to be released sooner.  "It will tell us why [Zimmerman] just disregarded, just ignored the police instructions when they tell him to stay put, they'll be there in a few minutes. On those 911 tapes is going to tell you why he said he's not going to follow their instructions. And most importantly, it's going to tell us his mentality when he confronted this 17-year-old kid," Crump said.  Numerous attempts to contact Zimmerman by CNN were unsuccessful, and it is unclear whether Zimmerman has retained an attorney.  Under intense pressure from the community, city officials in Sanford held a press conference on Monday.  "We are going to complete a thorough and fair investigation and present all the information to the state attorney's office so justice can be rendered," Lee said.  Police said they have not charged Zimmerman because there are no grounds to disprove his story of what happened.  "The evidence and testimony we have so far does not establish that Mr. Zimmerman did not act in self-defense. We don't have anything to dispute his claim of self-defense, at this point, with the evidence and testimony that we have," Lee said.
Answers remain in short supply as to why an unarmed teenager was shot and killed two weeks ago.Trayvon Martin, 17, was walking toward his father's home in a gated community in Sanford, Florida,...