It's a kind of philosophical issue at root. Parallels can be seen in the both the Death Penalty in the US vs. UK and more generally in Innocent Until Proven Gui

It's a kind of philosophical issue at root. Parallels can be seen in the both the Death Penalty in the US vs. UK and more generally in Innocent Until Proven Guilty in both legal systems. In the UK the death penalty was abolished because it is untenable that one innocent is killed accidentally. Innocent until proven guilty (and I might be mistaking the actual thing here) means that it is indeed better for 10 guilty people to walk free than 1 innocent person be imprisoned. If we reject some of these fundamentals for how we run our societies then we might repeat of the Terror during the French revolution. During the Terror they said "well, the mob cant be controlled, but it generally did good." Political philosophy and History can teach us many things.