Vanessa Guillen's family reacts to US Army report that murdered soldier was sexually harassed

In an exclusive interview with ABC News, the sister of Spc. Vanessa Guillén spoke about the family's reaction to a new investigation by the U.S. Army that confirmed their long-standing suspicions that a supervisor sexually harassed the soldier before she was murdered last year.

The report said leaders in Vanessa Guillén's unit at Fort Hood, Texas, did not take appropriate action after she stepped forward to report the two incidents of harassment.

Twenty-one soldiers have since been reprimanded or disciplined as a result of their handling of Vanessa Guillén's case.

Mayra Guillén said her family is relieved that the Army finally backed their claims and that some disciplinary action has been taken.

Still, the report did not name the supervisor who harassed Vanessa Guillén.

Mayra Guillén said her family feels the Army needs to do more to hold those responsible for her sister's harassment accountable.

"The Army keeps trying to protect this name and I want to understand why," she said of Vanessa Guillén's harasser. "Why not just try to take a step forward, admit that you were wrong, fix it and make yourself look better so, the nation could trust you again."

Army Spc. Aaron Robinson is believed to have murdered Vanessa Guillén on April 22, 2020, the day she disappeared from the base, according to authorities. Robinson died by suicide on June 30, 2020, as police closed in on him.

The Army's report found "no credible evidence to conclude Spc. Robinson sexually harassed Spc. Guillén or that they had any relationship outside of their work setting."

Natalie Khawam, an attorney representing the Guillén family, told ABC News that the day the report came out, the family was devastated. She blasted the Army for failing to take Vanessa Guillén's claims seriously in the first place and for not keeping an eye on Robinson when he was under suspicion for her disappearance.

"People reported it, she reported it to her fellow soldiers, and yet it all fell on deaf ears," Khawam said.

Since the incident took place, the Army has taken measures to make sure nothing like it happens again.

Last December, the Army fired or suspended 14 officers and enlisted soldiers at Fort Hood, including two generals, following an independent panel's investigation into the command climate at the base.

Six of the soldiers relieved of their duties in December were among the 21 soldiers who received administrative punishments as a result of the investigation released on Friday.

Mayra Guillén said the family is still struggling to process Vanessa Guillén's death, but they are also committed to changing the system. Mayra Guillén has joined Congress members and other activists to push for the passage of the "I Am Vanessa Guillen Act."

The legislation would create an independent system where service members would be able to safely report sexual misconduct cases without fear of retaliation. It would also move prosecution decisions out of the hands of the chain of command and make sexual harassment a punishable crime under the Uniform Code of Military Justice.

Khawam told ABC News that the bill is slated to be re-introduced to Congress this month.

Mayra Guillén said the family hopes that her sister's death can push the U.S. government to address sexual harassment in the armed services

"We're still looking to work very hard on this so we can put an end to it and not have what happened to Vanessa happen to anyone else ever again," she said.

ABC’s Jim Ryan reports for ABC News Radio:

ABC News' Luis Martinez contributed to this report.