MKUltra record destruction (1973).
documentedeventBlack-Project Lore
DCI Richard Helms and Sidney Gottlieb ordered most MKUltra files destroyed in 1973; the program survived scrutiny only via ~20,000 misfiled financial records surfaced under a 1977 FOIA.
Documented. The deliberate destruction is itself part of the record; it explains why the surviving evidence is financial paperwork rather than research files, and why much of MKUltra's specific human toll is unrecoverable.