The illegal immigrant charged with killing 21-year-old Sarah Root while street-racing drunk, entered the U.S. as an “unaccompanied child” three years ago, according to Immigration and Customs Enforcement.

Edwin (aka Eswin) Mejia, an illegal immigrant from Honduras, absconded after ICE declined to detain him following his arrest and posting bail. Mejia remains at-large and is currently on the ICE Most Wanted list.

In a letter to Sen. Ben Sasse (R-NE) responding to a series of his questions, ICE Director Sarah Saldana revealed that Mejia was initially apprehended when he entered the country illegally in 2013 but was granted the special treatment afforded to detained unaccompanied minors from noncontiguous countries, released into the U.S. and never deported.

The answer portion of Saldana’s letter reads:

In May 2013, Edwin Mejia was encountered by the U.S. Customs and Border Protection, U.S. Border Patrol (USBP) near Nogales, Arizona, after entering the United States without inspection. At the time of this encounter, Mr. Mejia was 16 years old and determined to be an unaccompanied child. Shortly after the initiation of removal proceedings against him with the issuance of a Notice to Appear, he was transferred to Department of Health and Human Services; Office of Refugee Resettlement (ORR), as required by law. Mr. Mejia had no recorded criminal history in the United States at this time.

“In June 2013, consistent with applicable law, ORR released Mr. Mejia to his brother in Tennessee. In early 2014, Mr. Mejia relocated with his brother to the Omaha, Nebraska area,” the missive added.

According to the letter, Mejia’s next immigration hearing before an immigration judge was scheduled for April 19, 2016.

In January 2016, Omaha police arrested Mejia after he crashed into Root’s vehicle, allegedly while street-racing drunk. The crash killed Root. ICE has stated that it did not file a detainer against Mejia because his crimes “did not meet ICE’s enforcement priorities.”

In the letter, Saldana walked back the argument that Mejia’s crimes did not meet the “priority” standard.

“After further review, we believe that further enforcement action would have served an important federal interest in this case, as provided for in Secretary Johnson’s November 20, 2014 civil immigration enforcement priorities memo,” she wrote.

Monday Sasse expressed frustration with Saldana’s approach to the Mejia case. Calling her letter “bureaucratic nonsense,” Sasse took the matter to Department of Homeland Security Sec. Jeh Johnson. Sasse wrote in a letter to Johnson:

ICE’s response does not attempt to answer why it did not detain an illegal alien who killed an innocent woman and is now on the run as one of ICE’s most wanted. Director Saldana’s handling of this matter shows no regard for the Root family and continues to be an embarrassment to the hard-working men and women at the Department of Homeland Security. I am referring my questions to your office and look forward to a thorough response as soon as possible.

In his letter to Saldana and Johnson, Sasse asked: