Do illegal aliens commit more crime than their lawful immigrant and legal U.S. citizens? That’s a question that has been repeatedly raised in the ongoing debate about American immigration policy. And the answer is likely to influence the degree to which American voters support measures such as the construction of a southern border wall.

Open-borders advocates and the mainstream media constantly argue that it’s a settled issue — illegal aliens are far less likely to commit crimes than citizens or even lawfully present immigrants. They argue that illegal aliens don’t want to draw the attention of law enforcement and risk deportation from the United States, so they stay on their best behavior.

Unfortunately, this couldn’t be farther from the truth.

A new study released by my group, the Federation for American Immigration Reform (FAIR), found that illegal aliens are, on average, more than three times as likely to end up behind bars as their non-illegal peers. The report, which covered 10 states that together comprise 65 percent of the nation’s total illegal alien population, should put to rest the question of illegal alien criminality.

Overall, the report found that more than 110,000 illegal aliens were reported as incarcerated in state and local detention facilities within the covered states. In California, which boasts the largest illegal alien population in the country, illegal aliens are more than three times as likely to be incarcerated as non-illegal aliens. The state with the largest incarceration disparity is New Jersey, where illegal aliens are five and a half times as likely to end up in jail.

Notably, this report does not include illegal aliens who have committed federal crimes, including most immigration-related crimes, meaning that the numbers in the study are by far on the conservative side.

These conclusions came from the most recent data reported to the federal government via the State Criminal Alien Assistance Program (SCAAP). The program reimburses states for a small portion of the costs incurred while incarcerating illegal aliens. The fact that SCAAP reporting covers known illegal aliens with criminal convictions, makes it a reliable dataset that can be effectively reviewed in conjunction with state-reported incarceration rates for non-illegal aliens.

What conclusions can reasonably be drawn from the findings?

When the relevant data is subjected to frank examination, the open-borders narrative that illegal aliens are less likely to commit crimes than citizens and lawfully-present aliens is shown to be patently false.

The anecdotal evidence lines up with the statistical evidence. Most Americans who pay attention to the evening news have long had a gut feeling that we have an unacceptably large number of illegal aliens committing serious crimes in the United States. Their intuition appears to be correct.

When making immigration policy, we have to be honest about the facts. In this case, the facts seem to show that illegal aliens commit crimes at a much higher rate than the rest of the population. This is yet another argument for the president’s border wall to prevent illegal immigration, and mandatory E-Verify to lock illegal aliens out of the job market if they manage to get in anyways.

Inevitably, the study will be criticized by those in favor of mass-migration and amnesty. A common claim is that SCAAP is an unreliable source of data because there’s a chance that some illegal aliens could be counted twice during the same calendar year. Or they’ll rely on mathematical smoke and mirrors, asserting that SCAAP data can’t accurately be compared to other information on state prisoners without significant “refinement.”

The fact is such concerns are vastly overblown. In order for inmates to be included in SCAAP, they must be confirmed illegal aliens who have been convicted of at least one felony or two misdemeanors. On average, the illegal aliens reported to SCAAP are incarcerated for more than six months. Additionally, the cycle-time from arrest to conviction also takes months. Taken together, these factors indicate that it would be rare for criminal illegal aliens to show up on SCAAP records more than once per calendar year.

Much of the research on illegal aliens and crimes is tainted by a deliberate attempt to ignore such data, thus downplaying the public safety issues pertaining to illegal immigration. However, until legislators are able to review accurate information about the rates at which illegal aliens commit crimes, they’ll continue making bad immigration policy. And too many Americans will continue to be the victims of preventable crime.

Spencer Raley is a research associate at the Federation for American Immigration Reform, a nonprofit group that advocates for legal immigration.