Immigrants, especially those living in the country illegally, are often reluctant to report crime when it happens to them.
So when police in cities from Austin to Nashville learned last month that the Bush administration is considering enlisting state and local police to help the federal government find and deport illegal immigrants, they balked.
''If we are forced to do this, you can just throw the trusting relationship that we built with this community out the window,'' says Rudy Landeros, Austin's assistant police chief.
''The Austin Police Department will not stop, detain or arrest individuals solely based on their immigration status. Period. Our job is to protect and serve everybody, regardless of their gender, religion or immigration status,'' Landeros says.
More than 8 million foreigners are in this country illegally, according to government estimates. And there are just 2,000 immigration agents to enforce the laws.
Police around the country say they already have enough work without enforcing federal immigration laws.
''It is an unfunded mandate, which takes away the ability of local law enforcement to provide the same level of service to the community,'' says Mark Brewer, legal adviser to the Lake County Sheriff's Department in central Florida.
The Florida Department of Law Enforcement, however, is negotiating with the Immigration and Naturalization Service (INS) about assigning 35 Florida officers to seven task forces to be set up to investigate terrorism in different regions of the state.
Al Dennis, a spokesman for the Florida police agency, stresses that the 35 officers would play a limited role once the agreement is finalized. Details of the officers' duties are not yet worked out.
''This is not about going out and raiding migrant workers' camps,'' he says. ''This is strictly limited to specific duties.''
Police in other cities say they are willing to help federal agents with specific requests. Nashville police spokesman Don Aron noted that his department has already assigned officers to task forces run by the FBI and the Bureau of Alcohol, Tobacco and Firearms that were set up after the Sept. 11 terrorist attacks.
''But this police department is not interested in having our officers become quasi-INS agents,'' he says.
In Austin, Landeros says: ''We understand the aftermath of Sept. 11. But we have to stop this problem we have here in Austin, and unless we do, the murders will continue and the robberies will continue.''
The Justice Department proposed that local police help pick up people for possible immigration violations as a way to combat terrorism. All 19 hijackers on Sept. 11 were living in the USA on temporary visas. Two were in violation of their visa requirements.
The Justice Department issued a short statement last month describing the proposal as part of exploring ''many options to enforce immigration laws.''
If adopted, the plan would reverse a 1996 legal opinion by the Justice Department that prevents local officers from making arrests for immigration violations.
Immigrants' rights groups and civil libertarians oppose the Justice Department plan because they say it could lead to widespread racial profiling by police.