Sure. The investigator can summarize findings, then provide either summaries of the testimony, or the actual interviews with names redacted, etc. Photos of Zimmerman's injuries and a description of the exact cause of Martin's death (bullet entry point); any other relevant forensic evidence, like powder burns on Martin's palm or palms, could also be made public without bringing charges. All at the investigator's discretion.
If there is a grand jury and a trial, grand jury testimony comes right in. The defendant is entitled to it, and so is the public.
Then if the reports are finalized it should move right along. It was reported that State AG who was assigned case may make decision and not take it to Grand Jury. She better have her ducks in line.