The border town of El Paso, Texas is considered to be the safest big city in the country, according to some estimates.
With a sizable undocumented population and immediate proximity to Ciudad Juarez, Mexico, known for drug cartel violence, El Paso's relative tranquility has baffled many, especially those who equate undocumented immigration with increased rates of violent crimes.
To researchers such as Jack Levin, a criminologist at Northeastern University, El Paso is safe precisely because of its high number of immigrants.
"If you want to find a safe city, first determine the size of the immigrant population," Levin said in an interview with Reason Magazine.
"If the immigrant community represents a large proportion of the population, you're likely in one of the country's safer cities," he added. "San Diego, Laredo, El Paso -- these cities are teeming with immigrants, and they're some of the safest places in the country."
In the national immigration debate, those who support stronger enforcement policies often justify their hard line with the argument that immigrants commit violent crime in their new-found communities at high rates. But critics say numbers don't support this reasoning.
Ruben Rumbaut, a sociologist at the University of California, Irvine who studies criminal immigration trends, said his research supports Levin's thesis.
"Studies that I have done based on census data, studies along the border, government commissions from 1994 to present, they repeatedly have found the same thing," he said in a phone interview. "Immigrants are associated with much lower rates of crime and incarceration. And some of the safest cities are those with large immigrant populations."
Although the majority of undocumented immigrants are thought to be foreign-born Mexican nationals, Rumbaut said that his research indicates this population has a much lower incarceration rate than Americans of Mexican descent.
"Foreign-born Mexicans had an incarceration rate of only 0.7 percent in 2000, more than 8 times lower than the 5.9 percent rate of native-born males of Mexican descent," he said.
So why might immigrants have a lower incarceration rate?
"The vast majority of immigrants who come to the United States do so to seek a better life," Rumbaut said. "Committing crimes would undermine the very project that would lead them to leave their country. In the case of the undocumented, the effect is magnified. They are living clandestine lives, under the threat of deportation. The last thing they want to do is bring themselves to the attention of authorities."
Rumbaut said he believes that violent crimes along the border with Mexico have little to do with the average undocumented immigrant. Instead, he said, a small percentage of those in the country who are undocumented and involved in drug or human trafficking have given the majority a bad name.
"These people have absolutely nothing to do with immigrants," he said.
Others, however, say Rumbaut's argument ignores the danger posed by the percentage of undocumented immigrants who do commit violent crimes. Howie Morgan, the national political director of the Minuteman Project, a volunteer border militia group, said in a phone interview that his conversations with enforcement agencies have given him a different picture of undocumented immigrants.
"We've talked to sheriffs all across the nation who say they have an inordinate percentage of illegal immigrants in their jails who have committed crimes. The drug trade, for example, is completely run by illegal aliens," he said. "These things should scare all Americans."
CRIME ON THE BORDER
This year alone, the Department of Homeland Security reported the deportation of "1,119 aliens convicted of homicide; 5,848 aliens convicted of sexual offenses; 44,653 aliens convicted of drug related crimes; and 35,927 aliens convicted of driving under the influence."
Those figures have become a rallying cry for those who support a government crackdown on undocumented immigration.
In her book "Scorpions for Breakfast," Arizona Gov. Jan Brewer cites Arizona Sheriff's Larry Dever's testimony before the Senate Committee on Homeland Security, endorsing the notion that "American citizens are terrorized, robbed, and murdered by the ruthless and desperate people who enter the country illegally."
Brewer wrote that one crime on the U.S.-Mexico border in particular spurred the passage of Arizona's controversial immigration law SB 1070, which gives police in that state the power to question a person about his or her immigration status if they suspect the person is undocumented.
She repeatedly suggested in her book that an "illegal alien" slayed the rancher Robert Krentz, although the crime remains unsolved. Investigators found footprints near the crime scene, Brewer wrote, that led across the border to Mexico. Brewer used Krentz's death as a symbol of what she said was rampant border violence generated by undocumented immigrants.
At the height of the SB 1070 debate, however, Arizona had never been safer, even with the spike in undocumented immigration, The New York Times reported. FBI statistics indicated that violent crime actually fell to 447 incidents per 100,000 residents in 2008, compared to 532 incidents per 100,000 in 2000. According to the same report, property crimes also fell during the same period.
Brewer did not respond to a request for comment.
ON THE OTHER SIDE OF THE FENCE
While a handful of studies suggest that undocumented immigrants are more likely to commit crimes, many remain unconvinced.
The Federation for American Immigration Reform, which calls for a reduction in legal and undocumented immigration, takes the position that those who "violate immigration laws are more likely to violate other laws."
Bob Dane, a FAIR representative, called it a "continuum of crime" -- once an undocumented immigrant is in the U.S., he or she must violate other laws to remain here, such as seeking employment without legitimate documentation and driving without a license, he said.
FAIR has dismissed the statistics cited by Rumbaut and other academics as "misleading," saying that the numbers often lump legal and undocumented immigrants together or rely on incomplete census data.
"It's nearly impossible to collect accurate crime statistics; so there's a lot of guesswork involved," Dane said.
Still, FAIR released its own report in 2007 based on government data it said was more reliable and reinforced what it called the link between "illegal aliens and higher incidence of crimes." The group concluded that there is a "clear pattern both nationwide and in the states with the largest estimated illegal alien populations of a higher rate of incarceration of aliens than for the non-alien population."
Rumbaut, whose own research on the subject found almost opposite conclusions, called FAIR's 2007 report "evidence-optional" and "misleading," saying the sample was biased and unreliable.
At a panel discussion last month on immigration and crime, Jessica Vaughan, director of policy at the Center for Immigration Studies, which advocates a crackdown on undocumented immigration, said her group's research "found no strong evidence one way or the other for the notion that immigrants commit either more or less crime than the American population."
Judith Gans, who studies immigration at the Udall Center for Studies in Public Policy at the University of Arizona, told The New York Times that "both sides in the immigration debate accept information that confirms their biases... and discard, ignore or rationalize information that does not."
In the absence of a consensus on the numbers, Rumbaut said, the immigration debate will continue to be tainted by the "enduring power of popular myths and stereotypes."
WATCH: Jan Brewer Cites Krentz's Death As Rallying Cry For Increased Border Security
Andrea Long-Chavez contributed reporting to this article.