Two papers on what seems to work against crime and homicides

1) Violence in and Around Entertainment Districts: A Longitudinal Analysis of the Impact of Late‐Night Lockout Legislation by Mazerolle et al. 

Our research shows that 3 a.m. lockout legislation led to a direct and significant reduction in the number of violent incidents inside licensed premises. Indeed, the lockouts cut the level of violent crime inside licensed premises by half. 

That is from the abstract. Unfortunately I did not find the paper. 

2) The Effect of Education Policy on Crime: An Intergenerational Perspective by Meghir, Palme, and Schnabel.  

 . . . [E]ducation policy, which increases compulsory schooling, can reduce the crime rates of the children of those directly affected by the reform.