The Washington Post explores “predictive policing,” the use of computer algorithms to forecast where and when crime will occur, or who might be a perpetrator or a victim. It represents a paradigm shift that is sweeping police departments across the country. Now used by 20 of the nation’s 50 largest police forces by one count, the technologies are at the center of an increasingly heated debate about their effectiveness, potential impact on poor and minority communities, and implications for civil liberties. “The hope is the holy grail of law enforcement — preventing crime before it happens,” said Andrew G. Ferguson, a law professor who studies big data and policing.
Some police departments have hailed PredPol and other systems as instrumental in reducing crime, focusing scarce resources on trouble spots and individuals and replacing officers’ hunches and potential biases with hard data. But privacy and racial justice groups say there is little evidence the technologies work and note the formulas powering the systems are largely a secret. They are concerned the practice could unfairly concentrate enforcement in communities of color by relying on racially skewed policing data. And they worry that officers who expect a theft or burglary is about to happen may be more likely to treat the people they encounter as potential criminals.