Darius M. Rejali said this quote

“ But *why* do clean torture and democracy appear to go hand in hand? This is an important puzzle (though by no means the only one suggested by the data). My explanation for this pattern generally is this: Public monitoring leads institutions that favor painful coercion to use and combine clean torture techniques to evade detection, and, to the extent that public monitoring is not only greater in democracies, but that public monitoring of human rights is a core value in modern democracies, it is the case that where we find democracies torturing today we will also be more likely to find stealthy torture. ”