Stalin took over my crossword!

Yesterday we were met with a tricky clue in the daily Advertiser crossword.

The word was 8 letters long and we already had _A_T_R_A.
It should have been easy, right?
We had no idea where to start and no way for extra help from cross words.

Eventually we realised that ACT might be law, and therefore since the Stalin is secret policeman had adopted law that might mean that _ _ R _A might somehow be a Stalinist secret policeman.... but we had to figure out that bugs (the straight clue) was probably BACTERIA (thanks Trev for that flash of brilliance) and then to look up Beria to find that he was the head of secret police in the time of Stalin.
Boy , that was a tough one!

So often we could do better at these if our general knowledge was better.

Here is the completed picture