Law enforcement agencies struggling to fill their ranks or connect with their increasingly diverse populations are turning to non-citizen legal immigrants to fill the gap.

Most agencies in the country require officers or deputies to be U.S. citizens, but some are allowing immigrants who are legally in the country to wear the badge. From Hawaii to Vermont, agencies are allowing green-card holders and legal immigrants with work permits to join their ranks.

At a time when 25,000 non-U.S. citizens are serving in the U.S. military, some feel it's time for more police and sheriff departments to do the same. That's why the Nashville Police Department is joining other departments to push the state legislature to change a law that bars non-citizens from becoming law enforcement officers.

Department spokesman Don Aaron told USA Today they want immigrants who have been honorably discharged from the military to be eligible for service.

"Persons who have given of themselves in the service to this country potentially have much to offer Tennesseans," he said. "We feel that ... would benefit both the country and this city."