So how did you decide there were only 2 guilties in column b?

So at the point just before your screenshot, the two clues that get highlighted for me are D3 and B2, which are the one’s I mentioned.

• D3 is the clue that tells us there is only one innocent left to reveal around C4, meaning there is one innocent and one criminal between B4 and B5, though we don’t know which is which yet. And with B2 already being a criminal, B1 being criminal would give use three in the column.

• B2 tells us column A is the only one with three criminals, so to fit all the clues, B1 has to be innocent.

I tried to indicate 1&2 in column d and it said I didn’t have enough evidence. That seems like a big problem in the intended logic.

For D1 and D2, we don’t have enough information before B1 is revealed because the options of them both being criminals or both innocent each fit the clues up to that point, making the choice a guess. After B1’s clue, the choice is clear.