Fort Worth and Tarrant County have had their differences over the years, but more often than not, leaders of the two entities have found ways to work together on residents' behalf.Cooperation broke down in a major way 11 years ago over dealing with people arrested by Fort Worth police, but elected officials have a new opportunity to improve the functioning of the criminal justice system -- and save taxpayers' money.First, a bit of history.When Dee Anderson was first elected Tarrant County sheriff 12 years ago, his office was in charge of securing county prisoners, but the county jail also contracted with the city to house individuals arrested by Fort Worth police and/or adjudicated on municipal charges.In 2001, Fort Worth officials decided they could save as much as $700,000 annually by ending the city's 16-year relationship with the county and signing a deal with Mansfield to incarcerate those prisoners who had been placed at the downtown jail.Mansfield had built a law enforcement center in 1990 with the intent of running an income-producing jail. That facility had plenty of space because it had lost a contract to house more than 200 prisoners from Oklahoma and was facing more competition from other for-profit prisons in the state. Mansfield was losing money while still servicing the debt on the $10 million facility.Some opponents of hauling prisoners to Mansfield warned that using a jail more than 20 miles (and about a 30-minute drive) from downtown Fort Worth would have unforeseen costs in addition to the inconvenience it would present for police officers, attorneys, bondsmen, detectives and inmates' families. And they were right.This year, Fort Worth is paying Mansfield $5.7 million for the service, plus $145,000 for private security for inmates who are hospitalized. Both expenses are scheduled to go up next year.A consulting firm that studied three alternatives to housing prisoners in Mansfield gave Fort Worth City Council members some estimates this week: renovating a former state jail facility owned by the city on Blue Mound Road would cost $179 million over 20 years, and building a new city jail would have a 20-year cost of $186 million. The price of contracting again with Tarrant County hasn't been determined, but it might be the best plan.Anderson told the Star-Telegram Editorial Board in a telephone interview that he is "more than willing" to accommodate the city and that the county jail has the space. He said he simply wants any contract to cover the costs -- not to make a profit -- by providing a book-in fee, a book-out fee and a daily rate for holding inmates.Only "casual" discussions have occurred so far, Anderson said, but city and county administrators plan to talk specifics after Thanksgiving.Both rising costs and logistical issues seem to argue against continued use of the Mansfield facility. It also appears that building a new jail should be taken off the table if it would be more expensive than renovating a city-owned facility.But the public's best interests could be served if the city works on a deal with the county that would eliminate duplicate services, reduce the need for cross-county transportation, and improve efficiency by putting inmates closer to courts and other justice system services.The goal should be to find a solution that serves all the stakeholders, including taxpayers.