The arrests were routine. Two women were taken into custody after they were discovered peering into cars in a downtown parking garage in Santa Cruz, Calif. One woman was found to have outstanding warrants; the other was carrying illegal drugs.

But the presence of the police officers in the garage that Friday afternoon in July was anything but ordinary: They were directed to the parking structure by a computer program that had predicted that car burglaries were especially likely there that day.

The program is part of an unusual experiment by the Santa Cruz Police Department in predictive policing — deploying officers in places where crimes are likely to occur in the future.

In July, Santa Cruz began testing the prediction method for property crimes like car and home burglaries and car thefts. So far, said Zach Friend, the police department’s crime analyst, the program has helped officers pre-empt several crimes and has led to five arrests.