From the get go Trayvon Martins parents have shouted loudly 2 things. 1) their sons innocence, and 2) they just want the legal system to be allowed to work.
It is perfectly natural for a parent to proclaim their child innocent of anything and everything. The fact that they were not there is irrelevant. As to letting the system work, once GZ was arrested and charged, the system allows for such things as bail hearings which happened last week. That the system progressed to that point as it was supposed to, and that the judge allowed bail, as is within his latitude apparently is NOT what the Martins want. They were upset that the system which they were so in support of worked as it was supposed to.
Face it. The parents of Trayvon Martin do not want the legal system to work, they want it to hang the killer of their little boy. Period. If the court system ultimately finds there is not sufficient evidence to convict GZ of 2nd degree murder there will probably be riots. Certainly there will be (if there is not already) a lawsuit seeking massive damages for the killing.
Whether or not it really was self defense will be of no concern to them and will be lost in a cloud of litigation. Which brings me to a main point. Civil action should be delayed by law until the criminal case has run its course. To often an individual or company is severely damaged or even ruined by civil actions and subsequently proven innocent of any crime.