Yes. Suspicion is common and this is, in part, due to the amount of lying at the highest levels of government (even by today's standards, it was out of hand).

It was an ugly period of history. It's very possible that something more was at work.

I tend to think that there was just a very ugly energy in the world at the time, where political violence (assassinations) was seen as a means to acheive one's goals. But who knows.