I have seen no report of the root cause for the Trayvon Martin tragedy - a poorly conceived and operated Neighborhood Watch Association (NWA).
Some important things remembered from the NWA's in Houston include 1) No firearms 2) a set of specific rules, signed off by each member 3) Observe and report only - don't leave your car. We used CB radios with a base station back then 4) minimum of 2 persons in each vehicle on patrol 5)A large magnetic NWA sign attached to the patrol vehicle, clearly identifying it 6) Regular meetings with law enforcement personnel in the area
Almost any one of the items noted could have prevented the needless death of Trayvon Martin, or at least provided the prosecution with a viable case.
If a community wants a higher level of protection, options include deputized, trained volunteers or a paid professional security service.