There are two problems:
I can't find the documentation in question. But people who know how I work, know about my credibility.
Secondly, you are too naive.
You really doubt that Americans, Israelis and MKO would not do whatever they can to spread lies about the 1988 killings? Pay Iranians? brainwashed MKO members?
Its basically the job of the Israelis to find things they can use against Iran on the international field, AI, BBC, VoA and so on, all work towards that. So yes, it's not a conspiracy theory that they do everything they can to use those killings against Iran.
I was lucky to have watched that documentary, which was anti-IRI, but still factual as many eye-witness were questioned. Top Tudeh party members told how much they feared to get executed too but then realized that only MKO members who stood with it after the betrayal were executed. Those top Tudeh members survived to tell this, but a simple leftist was killed?
I had the luck to watch that documentary, otherwise I would also have doubts. So I understand you, but at least don't portray it as fact.
At the end, I might be pro-regime or anti-regime but coincidentally, due to that documentation I have good knowledge about what happend in 1988, that's all.