BOSTON — Gov. Deval Patrick has unveiled a plan to reform the way the state’s criminal justice system handles mentally ill inmates, including a dramatic increase in staff at Bridgewater State Hospital.

The plan also calls for a new facility where potentially violent patients could receive care.

The plan, expected to cost $12.3 million in the short term and even more in the long term, calls for Massachusetts to move away from treating mentally ill people as prisoners and more like patients, including better training for staff.

Bridgewater, a prison run by the state Department of Correction, has come under fire for restraining patients too much and has been the subject of several lawsuits.

The facility treats both mentally ill patients convicted of crimes, as well as those awaiting trial.

The proposal would move many patients at Bridgewater to less restrictive facilities and says mentally ill people “should receive the appropriate care in the appropriate setting.”

Roderick MacLeish Jr., an attorney representing patients in one lawsuit, welcomes the proposal.

Advocates for the mentally ill also expressed hope.