Mollie Tibbetts' death is being used to push debunked ideas about illegal immigration and violent crime

Charlie Neibergall/AP

A missing poster for Mollie Tibbetts, a student at the University of Iowa who vanished in July and was found dead in August.

• The body of Mollie Tibbetts, a 20-year-old sophomore at the University of Iowa who went missing in July, has reportedly been found.
• Cristhian Bahena Rivera, an immigrant to the US from Mexico, was arrested on charges of first-degree murder in connection to Tibbetts' disappearance.
• Law-enforcement officials allegedly said Rivera is undocumented and in the country illegally, though the suspect's lawyer has disputed these claims.
• President Donald Trump and some right-leaning media outlets used the local news event to promote connections between illegal immigration and violent crime.
• However, statistics actually show illegal immigrants commit crimes at lower rates than native-born citizens.

Mollie Tibbetts, a 20-year-old sophomore at the University of Iowa, was last seen alive while jogging the evening of July 18. This week, authorities said they believe she had been killed and her body dumped in a corn field.

On Tuesday, police arrested Cristhian Bahena Rivera as a suspect. Rivera, an immigrant from Mexico, allegedly confessed to police that he pursued Tibbetts and later concealed her body, according to a warrant filed by the Poweshiek County Sheriff's office. Police also charged Rivera with first-degree murder, which in Iowa comes with a possible penalty of life in prison.

By Wednesday, law-enforcement officials said Rivera was undocumented and thus in the country illegally, and that he'd somehow passed the US government's E-Verify system as an eligible worker - allegedly because he used stolen identification, The Washington Post reported one law-enforcement official as saying. ABC News also reported that Rivera had worked for up to seven years at Yarrabee Farms, a company owned by Craig Lang, a former president of the Iowa Farm Bureau and "an active member" of the state's Republican Party.

The case is ongoing, and Rivera's lawyer reportedly disputed claims that his client is in the US illegally.

At the same time, many right-leaning politicians, figureheads, and media outlets appear eager to exploit the developments and push false narratives about illegal immigrants and violent crime.

How the right is trying to exploit Tibbetts' death

Charlie Neibergall/AP

Cristhian Bahena Rivera is escorted into the Poweshiek County Courthouse for his initial court appearance, Wednesday, Aug. 22, 2018, in Montezuma, Iowa. Rivera is charged with first-degree murder in the death of Mollie Tibbetts, who disappeared July 18 from Brooklyn, Iowa.

President Donald Trump, who in June 2015 falsely claimed that most immigrants from Mexico are rapists and drug-traffickers and recently approved policies that prompted the separation of thousands of migrant children, received extensive news coverage for weighing in on Tibbetts' death.

"You heard about today with the illegal alien coming in, very sadly, from Mexico and you saw what happened to that incredible, beautiful young woman," Trump said during a political rally on Tuesday. "Should've never happened. Illegally in our country."

Fox News chose Tibbetts' death to dominate its news coverage on TV and online Tuesday and, in a post on Wednesday, claimed several major media outlets "ignored" the "bombshell development" regarding Rivera's alleged status. (The news broke shortly after two of Trump's closest associates were convicted of crimes, one of whom - Trump's former lawyer Michael Cohen - implicated the president in several felonies.)

Meanwhile, Kris Kobach, the Secretary of State in Kansas and a Republican candidate for governor there, reportedly said of Tibbetts' death: "Every crime committed by an illegal alien is a crime that should never have occurred and would never have occurred if the illegal alien were not in our country."

What is implied in such statements is that fixing illegal immigration in the US will, by extension, effectively fix the country's violent crime rates.

This would be a compelling idea - if the best evidence available didn't show it to be very misleading, if not false.

What statistics actually show about crime and immigration

No set of data is perfect, and organizations that seek to restrict immigration have identified several issues with statistics regarding criminality and immigrant status.

However, multiple studies using federal and state data found no suggestion that rising immigration rates leads to more violent crime.

The charts below show that US saw a 118% increase in its overall immigrant population (documented and undocumented) from 1980 through 2016. Yet during this same period, the rate of violent crimes - homicide, rape, robbery, and assault, according to the FBI - fell by 36% to about 386 incidents per 100,000 residents.

Shayanne Gal

A study published in February by the Cato Institute, a libertarian think tank, further erodes the idea that curbing illegal immigration is the most effective way to reduce violent crime.

The study looked at conviction data in Texas - which has the second-largest population of foreign-born residents - for native-born, undocumented immigrant, and legal immigrant residents.

The research found that native-born residents were most likely to commit and be convicted of crimes, while illegal immigrants saw a conviction rate that was 56% lower. Legal immigrants appeared to be the most law-abiding, with 86% fewer convictions than native-born Texans.

There's also a Criminology journal study from March examining states' reported rates of violent crime and undocumented immigration. From 1990 through 2014, those data found a negative correlation - meaning that the more a population is comprised of undocumented immigrants, the lower the violent crime rate seems to be.

If anything, these studies suggest that increasing immigration - both legal and illegal - would lower crime rates.

Leanna Garfield and Shayanne Gal contributed to this report.