We study the effect of secondary education on criminal behavior of young men in Finland. We exploit admission cut-offs in over-subscribed programs and estimate the effect of gaining access to a) any secondary school vs no access, b) general vs vocational school, and c) selective vs less selective general school. Our results show that admission to any secondary school has a sizeable negative effect on the propensity to commit crime. There are no effects at the other two margins. The negative effects at the extensive margin are largest in the years following school admission and result in a reduction of the probability of ever committing crime rather than simply delaying the onset of crime. Our results suggest that keeping youth at school at a critical age has effects that last beyond years where effects on enrollment are observed.