The investigation of this event is being conducted under the jurisdiction of the Federal Bureau of Investigation (FBI). The NTSB provided requested technical assistance to the FBI, and any material generated by the NTSB is under the control of the FBI. The NTSB does not plan to issue a report or open a public docket.
Copied from Post #172. Seems that the FBI decides what is released publicly in this case, not the NTSB.