JENNINGS, Mo. -- St. Louis County authorities have begun experimenting with software to predict where crimes may happen.

The St. Louis Post-Dispatch reported two St. Louis County police vehicles are equipped with computers with software that predicts where crime likely will happen, based on mathematical algorithms.

St. Louis County Sgt. Colby Dolly, who oversees the recently created crime-analysis unit, said the software is "refining," not replacing, hot-spot policing, which has been around more than 20 years and forms patrol plans based on crime trends.

Dolly said the county paid $45,000 for the contract with HunchLab for the software.

The county is expected to pay about $35,000 for every subsequent year.

The system bases its prediction on several variables, including weather conditions, public transportation routes, vacant properties, foreclosures, parks, libraries and housing density.

HunchLab product manager Jeremy Heffner said one variable that is not used is race.

St. Louis County Police Chief Jon Belmar said this form of what is known as predictive policing is the future for law enforcement.

Officer Trevor Voss, one of the officers using the system, said a predicted gun-crimes area in Jennings did not surprise him, but a separate area identified for a high probability of car break-ins did.

"I would have never thought to look there," he said.