BOSTON (AP) — Lt. Gov. Timothy Murray is finding replacements to fill his leadership positions in Gov. Deval Patrick's administration before he formally steps down from office.

During his tenure as lieutenant governor, Murray has been involved with several ongoing issues, from trying to end homelessness to heading up efforts to reduce domestic violence in Massachusetts.

Murray's decision to resign on Sunday to head the Worcester Regional Chamber of Commerce has created a need to fill top policy positions.

Murray on Thursday announced that Housing and Community Development undersecretary Aaron Gornstein will take over his job of leading the administration's Council on Housing and Homelessness.

A goal of the Patrick administration has been to virtually end homelessness in the state, an ambitious plan that was dealt a blow by the downturn in the economy. Murray said, however, that the state has seen a 30 percent decrease in homeless families living in motels since November, 2012.

Murray also announced that Health and Human Services Secretary John Polanowicz and Public Safety Secretary Andrea Cabral will co-chair the Governor's Council to Address Sexual and Domestic Violence and Cheryl Bartlett, acting public health commissioner, will take over as head of the administration's Council on Substance Abuse and Prevention.

The appointments came one day after Murray announced that U.S. Rep. Joseph Kennedy will take over from Murray as chairman of the governor's Science, Technology, Engineering and Math Advisory Council.

Patrick established the advisory council in 2009 to help promote engineering and technology education in Massachusetts.

Murray called his experience on the various panels "extremely humbling" and said in a statement that he was confident the work would continue after he leaves because of the administration's strong leadership.