Pioneered in criminology, focused on the rights of the accused. He was upset at the practices of torture (thumbscrew, stretching body until bones broke) used, and the corrupted judges, secret trials, and usual death sentence.
Book: On Crimes and Punishment
He believed punishments shouldn't always be brutal and should fit the crime. The accused should have a fair, speedy trial (no torture). Advocated for public trials.
+ Right to remain silent