To arrest someone, you just walk to their ragdoll and they magically turn blue. It looks and feels weird, it can confuse new players who get arrested, and in dark areas it's hard to tell if you successfully arrested your target, even more so when there are dead bodies around because it makes the chat message unreliable.
I believe adding a ziptie or handcuff sound effect on arrests would be a very small improvement that would go a long way. To make sure it doesn't make arrests louder and less viable than they already are, consider making the sound effect