A widow from Missouri wants answers about her husband's death. His alleged killer is a Mexican man who was in the country illegally.

This week, Julie Nordman traveled to the nation’s capital to ask lawmakers how this could have happened.

Normand’s husband, Randy, was shot and killed in the couple’s New Florence home last year. His alleged killer is Pablo Serrano-Vitorino. Police were looking for Serrano after a killing spree that started in Kansas and ended with Nordman’s death.

Serrano is now facing charges for five different murders. Prosecutors in Missouri are seeking the death penalty.

U.S. Immigration and Customs Enforcement (ICE) said Serrano was deported once from the United States, but managed to re-enter the country illegally, again. Five On Your Side learned last year federal authorities knew he was back in the country but a mistake led to his release again.

In a statement from March 2016, ICE officials explained:

“On Sept. 14, 2015, ICE received an electronic notification that Serrano-Vitorino was fingerprinted at the Overland Park Municipal Court after receiving a fine for driving without a license. Although the notification prompted ICE to issue a detainer to the Johnson County Sheriff’s Office, Serrano-Vitorino was at court for a municipal fine and was never remanded to the sheriff’s office custody. Therefore, neither ICE nor the Johnson County Sheriff’s Office could take action on that detainer.”

“How did that happen? I don’t know.” asked Senator Claire McCaskill, during a hearing on Homeland Security and Governmental Affairs Wednesday morning.

“Why didn't ICE pursue Mr. Serrano further? I don’t know. What I do know is, six months later, Mr. Serrano allegedly shot and killed five men in Kansas and Missouri, including Randy Nordman.”

Nordman’s wife also testified at the hearing.

“Not only has ICE failed us, but our borders have failed us. They are obviously wide open as this man was able to enter, not once, but twice, without being detected,” she told lawmakers at the hearing, titled “The Effects of Border Insecurity and Lax Immigration Enforcement on American Communities.”

Nordman listed the other victims allegedly killed by Serrano in her testimony.

“If the ICE authorities had just done their jobs, Andrew Harter would still be alive. Clint Harter would still be a husband, and would have seen his second child being born. Mike Capps would still be alive. Jeremey Water would still be alive. And most importantly to me, my husband would still be here,” she said.

“Instead, every day that I’m at our house – I’m reminded of this tragic event. I wish you could bring my husband back, but we all know that can’t happen. What you can do is make sure that this doesn’t happen to another innocent family in the future.”

In her testimony Wednesday, McCaskill said she invited immigration officials to that hearing but they did not attend.

Law enforcement officials from Wisconsin and Washington also testified at the hearing.

ICE officials did not respond to a request for comment late Wednesday evening. However, in 2016, ICE officials said Serrano was on their radar for a long time, both before he was deported and after he returned. In some cases, ICE said police agencies would arrest him for various crimes but not notify immigration officials he was in custody.