PORTLAND – A program aimed at keeping mentally ill criminals in treatment instead of jail has been deemed a success in Maine’s Cumberland County. Now it’s being studied by other states considering similar approaches.

The Divert Offenders to Treatment program launched three years ago is a collaborative among corrections officials, police departments and mental health professionals.

As part of the effort, researchers tracked 10 people with a history of mental illness who’d been in and out of jail.

A combination of police sensitivity, early intervention in jail and treatment after release caused the number of repeat arrests to drop sharply.

There were two drunken-driving arrests and a probation violation but the program helped to prevent offenders from repeating serious crimes.

“The days in jail dropped dramatically and the number of arrests went way down,” said Paul Coleman, director of the program for Cumberland County.

A $900,000 grant got the program off the ground. The money paid for stipends to police officers who became certified in crisis intervention.

Police in Portland, South Portland and Westbrook learned to identify signs of mental illness and to help de-escalate the person’s behavior to reduce violent conflicts and the need for arrest.

The money also augmented Maine Pretrial Services, enabling staffers to check the jail regularly to determine whether anyone recently arrested would be better served by immediate and sustained mental health services.

The problem in Portland is acute because the city is a service center attracting many people, including those with mental illness.

Roughly 60 percent of the inmates at the Cumberland County Jail are receiving medication for psychological conditions.

“The problem was Cumberland County Jail was swimming in people with mental illness. There weren’t enough programs to get them out of there,” said Carol Carothers, executive director of the National Alliance for the Mentally Ill in Maine.

Spring Harbor Hospital, part of Maine Medical Center’s Psychiatry Department, was able to expand its assertive community treatment team so therapists could develop and track a person’s treatment plan once released from jail.

The teams are designed to make sure clients are adhering to their medications, help them find work and keep up with counseling.

Paul Ranucci, director of Maine Med’s program, says getting the criminal justice and therapeutic communities to work together has been a breakthrough.

“The mental health system and criminal justice system have not had communications bridges for many years,” he said. “We’re all finding we need to have much more collaboration with each other to meet demands on a shrinking budget and a changing system.”