Police officials statewide say some sheriffs' offices in Massachusetts, especially those in Middlesex and Bristol counties, have expanded their purview to law-enforcement activities that overstep their mission.

In Middlesex County, the sheriff's office has been criticized for its purchases of a mobile training center and armored ballistics vehicle to buttress its law-enforcement capabilities through federal grants. Meanwhile, Bristol County Sheriff Thomas Hodgson has irked police officials in Fall River and New Bedford for sending some of his men to those cities to help stem crime. 

Wayne Sampson, executive director of the Massachusetts Chiefs of Police Association, said the state's 14 sheriffs offices should primarily monitor the jails they oversee.