John, your suspicions are almost certainly quite correct. Even if we make allowances for the fact that denigrating Beria could have been a prudent thing to do in the years immediately after his fall, I don’t think that there can be much doubt about the appalling extent of his sadism. There are just too many seemingly well-authenticated accounts.
For what it’s worth (I mentioned it in NR at the time), I visited Beria’s house in Moscow at some point in the mid-1990s (it was then — and still is — the Tunisian embassy). The distinctly creepy cellars still contained more than a hint of the cells (and, reportedly, much worse) that they once housed, and rather too many human bones have been found on or near the premises than can easily be explained away.
I asked a Tunisian diplomat how how he felt about working in a building with a history like that. He replied that he didn’t believe in ghosts. Just as well.