Trump says Mollie Tibbetts' death 'should've never happened,' calls immigration laws 'a disgrace'

President Donald Trump called the United States’ immigration laws “a disgrace” Tuesday night, referring to the undocumented immigrant charged in the death of Mollie Tibbetts.

Trump, a Republican, was speaking at a rally in West Virginia. He said Tibbetts’ death “should’ve never happened.”

“You heard about today, with the illegal alien coming in from, very sadly, from Mexico,” he said. “And you saw what happened to that incredible, beautiful young woman.”  

Investigators in Poweshiek County charged 24-year-old Cristhian Bahena Rivera with first-degree murder in Tibbetts’ death. He’s being held on $1 million bond. Authorities said they conferred with the U.S. Department of Homeland Security, which told them Rivera is undocumented, even though he’s lived in the Brooklyn, Iowa, area for four to seven years.  

INVESTIGATOR:Suspect in Tibbetts' death 'hadn't come across the radar' until Monday

MORE:Read the criminal complaint, arrest warrant in the Mollie Tibbetts case

RELATED: Arrest in Mollie Tibbetts' death inflames immigration debate

“The laws are so bad,” Trump continued Tuesday. “The immigration laws are a such a disgrace."

The White House reiterated his comments in a tweet for it's 17.2 million followers.

Trump has long maintained a hard line on immigration from Mexico, consistently advocating for a border wall to separate the two countries. He mentioned the wall at his rally Tuesday, prompting the crowd to chant: “Build that wall.”

He echoed what Iowa Gov. Kim Reynolds said in a statement earlier in the day when she called the U.S. immigration system “broken.”

Trump went on to say that voters need to elect more Republicans in November’s midterm elections to prevent Democrats from opening the borders to let in “massive” crime.

Statistics say that immigrants, legal and otherwise, commit fewer crimes than native-born citizens.

"There's 100 years of data from all different sources that all point in the same direction," Walter Ewing, senior researcher at the American Immigration Council, which advocates on behalf of immigrants, told USA Today. "If you don't believe one study, there's 10 more behind it that say the same thing."

Ewing's research showed that from 1990 to 2013, the percentage of the U.S. population that is foreign-born increased from 7.1 percent to 13.1 percent. Yet over that time, violent crime rates plummeted 48 percent across the country.

Likewise, the libertarian Cato Institute concluded that the incarceration rate for native-born Americans is 1.53 percent compared with 0.85 percent for undocumented immigrants and 0.47 percent for legal immigrants. When Cato subtracted people in prison solely for immigration violations, the incarceration rate for undocumented immigrants fell to 0.5 percent.

​​​​​​More:Mollie Tibbetts murder case: Here are the facts on immigrants committing crimes in US

USA Today reporter Alan Gomez contributed to this story.