Cottonwood Heights celebrated the start of its new police force this week. The good news is it might be the last new police force formed in Salt Lake County.

We understand why Cottonwood Heights wanted to break away from the county sheriff's office. It's an age-old story. The sheriff's budget ultimately must be approved by the County Council and the mayor, and they budget with the needs of all county departments in mind. For cities that contract with the sheriff, such a politically laden system offers little assurance that individual cities will have their local needs considered in the budget.

And, of course, there are always anecdotal tales of crimes in which deputies took an unacceptably long time to respond.

But fracturing the county into several independent police departments, each with its own chief, policies and rules, is not a good thing for the people of Salt Lake County. The valley may be home to many cities, but most residents are quite mobile during the day. They live in one city and work in another, and they may shop or attend cultural events in yet another. And they may require police services from any of these cities, whether or not they pay taxes there.

Likewise, criminals do not necessarily confine themselves to city limits. A robber may hit a number of banks or convenience stores in several jurisdictions. A unified countywide police force would best be able to serve the 1 million or so people who live in Salt Lake County.

Earlier this year, state lawmakers passed SB253, a bill that allows the Salt Lake County sheriff to begin negotiating with police departments to form a unified police force. Such a force would be governed by a board on which would sit representatives from each city. This would ensure that cities have a bit more say in the budgeting process.

Efforts to form a unified police force have failed in the past, mainly because cities felt they would be losing too much control. Clearly, the best sort of policing effort would be one in which cities could control their own levels of response to crime, but in a cooperative way that coordinates law enforcement countywide.

That sort of thing may be impossible to achieve so long as the county contains several police chiefs, but it is a goal worth pursuing. SB253, which the governor signed into law, also specifies that if no unified police force has been established by May 5, 2009, the County Council can step in and negotiate one without the sheriff's approval.

We hope that prod works.