Oh that's a really good point actually. Cobalt who helped with the final push of the game actually suggested that as well. The tables are a bit taller than the cops and Gruntled, but it totally makes sense that even if that's the case, from the cameras perspective it should block their bullets.
I'll be sure to add benches and tables blocking bullets. I think the other thing is mainly the speed of the bullets. I kind of like the precise accuracy of the guard shooting, but I think maybe it would be good if they lagged a bit behind as you moved around, which would incentivize trying to get them to loose you.
Afroduck suggested also that this game could really benefit from difficulty settings. If it was level based there could be difficulty modes for each level, which could give the player the chance to learn the mechanics in previous difficulties before stepping up. I think the game currently is balanced for an Ultra Hardcore mode LOL.