On Monday, Pima County Sheriff Clarence Dupnik announced that he, Yuma County Sheriff Ralph Ogden and Maricopa County Sheriff Joe Arpaio support the idea that Arizona schools ask students whether they are legally in the United States. The sheriffs' plan challenges a 1982 U.S. Supreme Court ruling that K-12 public education is guaranteed for all children, regardless of their immigration status.

Dupnik's proposal ("Sheriffs: Are you in school legally?" April 28) undermines the future of Arizona. In a time of economic crisis, Arizona needs to emerge from the dark ages of punitive policies that marginalize immigrant families. We need leaders to be brave enough to chart a new course for the state that is forward-thinking and innovative.

The sheriffs said that they have not studied the research or looked to see what other states are doing. As a result, Arizona is going to be left behind.

The sheriffs cite two justifications for turning schools into immigration enforcers: crime and cost. On both accounts they are wrong. National and state research shows that immigrants boost the Arizona economy and contribute to lower crime rates.

Research studies examining the link between immigration and crime have repeatedly found that Hispanic immigrants commit less crime than native-born citizens. The nation's leading criminologists of immigration have drawn these evidence-based conclusions using actual data on rates of crime in the United States.

According to Raymond Michalowski of Northern Arizona University, "Despite years of research that immigrants are not a crime threat, some continue to promote the myth of Latino immigrant criminality, relying on falsehoods, anecdotes and half-truths."

The sheriffs claim that the state will save money by turning immigrant schoolchildren over to immigration. However, researcher Judith Gans of the Udall Center for Public Policy published findings in a 2008 report that "immigrants in Arizona generated a net 2004 fiscal contribution of about $940 million toward services such as public safety, libraries, road maintenance and other areas."

Surprisingly, the sheriffs reveal an oversimplistic understanding of immigrant families in Arizona. Because of backlogs in immigration-application processing and other administrative procedures, families have mixed immigration status. U.S. citizens, permanent residents, someone with a work visa and someone with an expired tourist visa are all likely to live under the same roof as a nuclear family. Involving our school system in dividing these families would be a disaster.

We should expect more from our law-enforcement leaders, whom we depend on to serve and protect our communities. But if our sheriffs are promoting the idea that schools become immigration-enforcement centers, they are shooting themselves in the foot by alienating immigrant families who should be seen as part of the solution to public safety rather than a threat.

In the meantime, while Arizona leaders keep us bogged down in debating where and how to round up schoolchildren, other states are recognizing the importance of a diverse, educated and highly skilled work force that can attract long-term businesses.

Oregon, New Jersey, Maryland, Colorado, Rhode Island, Missouri, Connecticut and Arkansas have all discussed providing in-state tuition to undocumented-immigrant youths this year. Other states are expanding support for English and civics classes and citizenship centers.

Punitive approaches don't work and are unrealistic. Our sheriffs should know better. Arizona has a tremendous opportunity to be an innovative state that integrates immigrant families into our schools, work force and communities.

We need leaders in Arizona that can pass the test of true leadership: breaking away from the pack and promoting solutions that are bold, meaningful and benefit the state as whole.