Republican presidential nominee former President Donald Trump arrives to speak at a meeting of the Detroit Economic Club, on Oct. 10.Julia Demaree Nikhinson/The Associated Press
Donald Trump has placed the spectre of a porous border at the heart of his re-election campaign. Countless criminals have snuck in on Democrats’ watch, he has said, 13,099 murderers among them.
“They’re roaming free,” he said at one recent rally.
“Thousands and thousands of criminals” are arriving in towns and cities, he warned at another. “All of a sudden your whole life changes – your whole life.”
Mr. Trump is expected to be in Aurora, Colo., on Friday, where Venezuelan migrants have been blamed for bringing violent gang activity onto U.S. soil. His claims have already inspired others to stir up fright. One post that has spread on social media suggests illegal migrants kill 4,000 people a year.
There is no reason to think that is true.
But Mr. Trump’s rhetoric has struck at a gap in the gathering of U.S. statistics. It is impossible to know exactly how many Americans die at the hands of undocumented migrants each year, because that information does not exist.
Trump says migrants who have committed murder have introduced 'a lot of bad genes in our country'
The information that does exist suggests violent crime is down overall in the United States, and that in any case foreign-born residents are less likely to commit criminal offences than lifelong Americans.
When Stanford criminologists scoured 150 years of data, they found persistently higher rates of crime among U.S.-born people. Today, a person born outside the country is 60-per-cent less likely to be incarcerated than a native citizen.
Those findings, however, provide no definitive insight into illegal migrants, “because we can’t tell in the data who is undocumented,” said Ran Abramitzky, one of the Stanford researchers.
Even county sheriffs cannot say with certainty how many migrants are in their own jails. In Canyon County, Idaho, for example, officers fill out unified citation reports when they make an arrest. Those reports inform national data. But they do not record migration status. “We don’t track any of that,” said Canyon County Sheriff Kieran Donahue.
Mr. Donahue, who was sworn in this summer as president of the National Sheriffs’ Association and regularly lectures on border security issues, nonetheless believes new arrivals play a significant role in American crime. Migrants often arrive in the U.S. indebted to cartel traffickers, he said, and their need for cash provides incentive for them to commit crimes.
“That’s a lot easier path than trying to go out and do landscaping or work in a hotel,” he said. But what begins as an attempt to scratch out a living “evolves into really serious, heinous, violent crimes,” he said.
Among migrants, he said, “there’s a lot more criminality than people are aware.”
In fact, statistics show that the opposite is more likely.
Some evidence comes from Texas, which unlike other states does track the immigration status of people who are arrested. Between 2012 and 2018, Texas arrest rates for violent crime among U.S.-born citizens were twice those for undocumented migrants, according to an analysis by sociologists at the University of Wisconsin-Madison. Property crime arrests were four times higher.
But such data are not available nationally, providing room for critics to make claims that cannot be thoroughly rebutted.
“In the absence of perfect data – and there’s no such thing – political rhetoric sort of fills that gap,” said Ramiro Martinez, a quantitative criminologist at Northeastern University.
That’s despite many indicators that suggest people born outside the U.S. are less engaged in violent crime. Parts of the country with higher numbers of immigrants, for example, report fewer homicides, Prof. Martinez said. In fact, the movement of more immigrants to an area over time often has a “suppressing effect” on crime, he said.
“Places with more immigrants tend to have less violent crime over time.”
The deaths of Laken Riley and Jocelyn Nungaray – a nursing student and a 12-year-old who authorities say were killed by undocumented Venezuelans in separate incidents – are shocking in part, he said, because they are unusual. Mr. Trump has referenced both deaths at public appearances during the presidential campaign.
“We notice it more because it’s so rare,” Prof. Martinez said.
For conservatives, such arguments have been overshadowed by government statistics that appear to show, as Mr. Trump has said, vast numbers of foreign criminals in the country. In late September, U.S. Immigration and Customs Enforcement, or ICE, provided a raft of statistics on non-citizen crime in a letter to Tony Gonzales, a Republican Congressman from Texas.
The letter counted 662,566 non-citizen criminals in the country, including 13,099 convicted of homicide who were not currently being detained.
That number has been repeated by Mr. Trump – but it has been badly misunderstood, according to the Department of Homeland Security, which oversees ICE. “Non-detained” means not currently in ICE detention. Many of those people are instead “currently incarcerated by federal, state or local law enforcement partners,” the department said in a statement.
More importantly, the data count every foreign-born person in the U.S. with a criminal conviction, including those who arrived more than 40 years ago. “The data in this letter is being misinterpreted,” the department said.
The overall rate of U.S. crime provides further grounds for doubt that recently arrived migrants are responsible for a crime wave. In the first six months of this year, FBI statistics show instead a considerable drop in violent crime compared to 2023, including a 17.7-per-cent decrease in rape and a 22.7-per-cent decrease in murder.
“Across regions, across cities and across crime types – it’s all down,” said Charis Kubrin, a criminologist at University of California Irvine.
Questions remain, she said. Most analyses of immigrant crime look at those who arrived in years past. They do not include those who have crossed into the U.S. in large numbers over the past few years. It will take time to assess whether the nature of those migrants is different in some fundamental way.
But she warned that the political focus on migrant crime can come at the cost of responding to issues that are greater contributors to violence.
“If we think we’re going to solve the ‘crime problem’ in this country by building a wall, or doing other really harsh policies aimed at immigrants – my take, based on working in this area, is that is not a good use of time, energy and resources,” she said.