Department of public safety

In the United States, a department of public safety is a state or local government agency which often has a broad portfolio of responsibilities, which may include some or all of the following:
These responsibilities are usually organized into separate agencies under a DPS due to their diversity, though there is a critical exception in certain local jurisdictions (as further explained below). 
In other countries, equivalent agencies may be known as the "ministry of the interior". In U.S. state or local governments that do not have a DPS, equivalent agencies may be known as the "department of emergency services".
United States.
Federal level.
The United States Department of Homeland Security is the federal-level department of public safety of the United States, which is responsible for federal supervision of emergency services for major disasters through the Federal Emergency Management Agency (FEMA).
State and territorial level.
In state governments in the United States, the DPS is often a law enforcement agency synonymous with the state police. At local and special district levels, they may be all-encompassing. Examples of states having these include Texas, Minnesota, Tennessee, Arizona, Alabama, Oklahoma, and South Carolina. In many states the state police may be a subdivision of the DPS and not its own independent department.
Local level.
Many local jurisdictions (cities and counties), and special districts (schools and hospitals) have the umbrella configuration described above, in which the DPS is simply a joint administration of several distinct agencies. They may share administrative support staff and back-office functions, but sworn personnel remain specialized and have particular responsibilities (that is, the police continue to arrest people and the firefighters put out fires). The DPS of Cobb County, Georgia is one example. 
However, a minority of jurisdictions have departments of public safety which have primary and direct responsibility for all emergencies. In these unusual organizations, all full-time sworn personnel are cross-trained as police officers, firefighters and EMTs, and can respond to emergencies in any capacity. Although it is more expensive to hire, train and retain such personnel, they have a clear advantage in terms of their flexibility. They can respond as first responders to many rapidly evolving situations rather than waiting for the arrival of other specialized personnel. 
This configuration was more widely popular in the 1970s and 1980s in the United States, but has since gone out of style because relatively few cities have been able to execute it successfully because of manpower limitations in handling major incidents.
In a few California cities (the Pasadena-area suburb of Duarte, for example), the department of public safety usually is restricted to code enforcement officers or animal control service agents (especially when those cities contract out for law enforcement with the county sheriff's office).
List of cities with departments of public safety with fully cross-trained personnel.
Alabama
Alaska
California
Florida
Georgia
Illinois
Indiana
Iowa
Kansas
Kentucky
Michigan
Minnesota 
Missouri
North Carolina
New Hampshire
New Mexico
New York
Oregon
Ohio
South Carolina
Tennessee
Texas
Utah
Washington
Wisconsin 