interrupted time series

When the law changes: The impact of a change in criminal justice policy on a long-term hot spot policing program

This study tested three competing hypothesis to explain a sudden increase of street robberies in Montevideo: 1) the failure of a hot spot policing program to maintain crime decreases; 2) improved crime recording by police patrols using tablet computers; and 3) the change from an inquisitorial to an adversarial criminal justice process. Using an interrupted time series approach with ARIMA errors, we found that the new criminal justice procedure was the most likely explanation for robbery increases.