The state Judiciary is expanding a probation program to Hilo after it helped reduce recidivism rates on Oahu and produced similar results in Maui County.

The program promises swift and certain jail time for probation violators.

Offenders in the program are warned that testing positive for drugs or missing an appointment with their probation officer will automatically result in jail time. The police track down no-shows. Drug test rules are also stricter.

Positive drug tests declined by 83 percent on Oahu, where the program was first tried. Participants were 55 percent less likely to be arrested for a new crime.

The program begins in Hilo today. Kailua-Kona’s distance from the Big Island’s only jail in Hilo is preventing the program from being used in courts there.