Just a thought re TWA 800! Under Annex 13, a law enforcement agency may parallel any investigation UNTIL it has been established whether or not a crime has been committed. IF the crash was indeed caused by an explosion in the centre tank, why does the FBI (who should have withdrawn) STILL refuse to release radar data and satellite photos?
Radar data germain to the accident is released by the NTSB. Other data including satelite images is either not germain to the accident based on other evidence or is classified since it would reveal capabilities that were not designed for aircraft accident reconstruction.
All such data that was pertinent was made available to the investigators. Data generated outside the official report as well as priveledged data is considered private by agencies/organizations other than the NTSB