Her testimony comes as part of her department is shut down amid funding fight.

WASHINGTON -- Secretary of Homeland Security Kristi Noem faced questions about immigration enforcement operations as she testified before the Senate Judiciary Committee on Tuesday -- refusing to apologize for or retract her statements about a U.S. citizen shot and killed by federal law enforcement in Minneapolis earlier this year.
Portions of the testimony focused on the shooting of a Chicago woman five times by a Border Patrol agent last October in the Brighton Park neighborhood.
When pressed by Sen. Dick Durbin, the top Democrat on the Senate Judiciary Committee, about why Noem labeled Alex Pretti, who was shot and killed by federal law enforcement in Minneapolis in January, a domestic terrorist without evidence, she would not admit she was wrong.

Durbin then asked, "Is it so hard to say you were wrong?"
"I absolutely strive to provide factual information and will continue to do that," Noem responded, adding that when the agency fails, they admit wrongdoing. Noem has yet to admit she has been wrong about how she characterized the Pretti shooting, as some have suggested.
In the hours following the Brighton Park shooting, DHS officials also labeled Marimar Martinez a "domestic terrorist".
Martinez was shot by Border Patrol agent Charles Exum Jr. and was subsequently arrested, but all criminal charges against her were dismissed with prejudice.
Democratic U.S. Sen. Richard Blumenthal of Connecticut questioned Noem about the Martinez shooting, but the secretary of Homeland Security testified under oath she knew nothing about the case.
Blumenthal asked, "Wouldn't you agree that shooting Marimar Martinez on her way to donate clothing at her church, a United States citizen from Chicago, is wrong?"
"Sir, I don't know the situation or the case," Noem replied. "I'll look into it."
"I'm glad you'll look into it," Blumenthal answered. "Marimar, by the way, was falsely charged with impeding law enforcement, but the case actually fell apart. The judge dismissed it as being trumped up."
After the shooting, Agent Exum was allowed to drive his federal vehicle, an important piece of evidence in the case against Martinez, back to Maine. Those actions are now part of an ongoing criminal investigation by the U.S. Attorney's office in Indiana.
Democratic U.S. Senator Adam Schiff of California asked Noem why an agent would be allowed to do this.
"You let an agent involved in an officer-involved shooting drive a key piece of evidence a thousand miles away, is that how you conduct investigations at DHS?" Schiff asked.
Noem answered, "I'm not conducting the investigations into these, the Department of Justice with the FBI are conducting these... The investigations into our officers have not changed under my leadership or the president's leadership."
Noem also said her characterization of Pretti -- whose conduct she called following the shooting "the definition of domestic terrorism" without evidence -- was based on information relayed to her in the hours after the incident.
Shortly after the shooting of Pretti, a Minneapolis Veterans Affairs ICU nurse, Noem drew criticism for insinuating he wanted to "massacre" law enforcement before the evidence and investigation was complete. Pretti was licensed to carry a handgun. Video from multiple angles showed that Pretti did not try to draw his gun from his waistband before or during the scuffle with federal agents.
Tuesday's hearing marks the first time Noem is appearing before Congress after tensions in Minneapolis and the killing of Pretti as well as Renee Good, who was shot and killed by federal law enforcement in Minneapolis in January.
Two Senate Republicans have said Noem should be out of a job, and Democrats have called for her impeachment. President Donald Trump has repeatedly said he stands by Noem.
Later in Tuesday's hearing, Noem said that there are no plans to deploy agents from Immigration and Customs Enforcement at the polling places in November after President Donald Trump recently doubled down on his controversial suggestion that Republicans "nationalize" elections, saying the "federal government should get involved" in elections.
"We have no plans to have ICE officers or law enforcement at polling locations. States are responsible for running their elections, and we're giving them tools and mitigation efforts that they can utilize in order to make sure they maintain the integrity of those elections, and that individuals can trust their systems to ensure that their vote counts," Noem said.
Noem's appearance on Tuesday marks the first of two days she is set to testify on Capitol Hill. She will testify before the House Judiciary Committee on Wednesday.
Her testimony comes as some parts of Noem's agency -- from the Federal Emergency Management Agency to the Transportation Security Administration to the Coast Guard -- are shut down amid a funding fight over Immigration and Customs Enforcement. Democrats have said they will fund the department only if changes are made to the agency in the wake of the shooting deaths of Good and Pretti.
WLS' Mark Rivera, Barb Markoff, Christine Tressel and Tom Jones contributed to this report.