In the wake of several violent incidents involving mentally ill individuals — including the murder of an Upper East Side psychiatrist in February — city and state officials yesterday announced a series of new policies designed to improve care for patients and reduce the risk of violence.

Based on recommendations from a joint state and city task force, Governor Paterson and Mayor Bloomberg outlined a series of bold changes within the adult mental health system and the criminal justice system, including increased information sharing between law enforcement authorities and those who care for mentally ill patients.

“While you can’t predict every violent incident, by implementing these recommendations we strengthen our system and offer a coordinated response to those who need it most,” Mr. Bloomberg said in a statement.

Within the criminal justice system, lawmakers plan to start a program that will share — when appropriate — a patient’s mental health information with law enforcement. A new, city-based “alternative-to-detention” program will also assess and supervise community-based treatments for mentally ill individuals who are charged with crimes. Further, the city’s probation department would establish a dedicated mental health unit, and more information about emotionally disturbed patients would be shared with police.

Advocates for individuals with mental illness praised the new policies. “Although exceedingly rare, violence by people with mental illness generally occurs when they are untreated,” the executive director of the Mental Health Association of New York City, Giselle Stolper, said in a statement.