Fort Hood soldier Vanessa Guillén, 20, disappeared on April 22, 2020, and was later found murdered
Vanessa Guillen

Fort Hood soldier Vanessa Guillén was sexually harassed by a supervisor, according to a recently-released U.S. Army investigation. 

The supervisor who sexually harassed Guillén was not the soldier, Army Specialist Aaron Robinson, who murdered her, according to the investigation.

Guillén's family had long said the 20-year-old small arms mechanic previously told them she had been a victim of sexual harassment at the hands of others in the military.

"We were taken aback not because they finally admitted the truth, but the fact that it took so long for them to admit the truth — over a year after she went missing and was murdered," Guillén family attorney Natalie Khawam tells PEOPLE. "We were telling them the entire time she was sexually harassed and they finally admitted it." 

The investigation concluded that Guillén was sexually harassed twice by one of her supervisors. 

"This supervisor created an intimidating, hostile environment," according to an executive summary of the 264 page report. "The unit leadership was informed of the harassment as well as the supervisor's counterproductive leadership, and failed to take appropriate action."

Vanessa Guillen
Vanessa Guillen
| Credit: US Army

The investigation concluded the sexual harassment of Guillén had nothing to do with her slaying.

Guillén went missing from Fort Hood on April 22, 2020. Sixty-nine days after she vanished, Guillén's body was found along the Leon River near Belton, Tx. She had been murdered and then mutilated.

The main suspect, Army Specialist Aaron Robinson, killed himself when confronted by police just hours after her remains were found. Authorities arrested his girlfriend Cecily Aguilar who is accused of helping to cover up her murder and dispose of her body.  She has pleaded not guilty. A trial date has yet to be set.

RELATED VIDEO: Vanessa Guillén's Fiancé Hopes Her Murder Will Create Changes in the Military

Investigators said they found "no credible evidence to conclude Spc. Robinson sexually harassed Spc. Guillén or that they had any relationship outside of their work setting, only that he had a work relationship with Guillén."

Khawam said the finding was "mind blowing." 

"Why do they continue to try to defend him?," she says. "No one saw anything or heard anything according to them. How do they know she wasn't sexually harassed? What else would he have been doing for him to murder her in a room alone? They need to step back and stop defending a murderer."

 According to the investigation, Guillén informally reported two incidents of harassment. The first incident was in her troop orderly room in the summer of 2019 when one of her supervisors made "an inappropriate sexual comment in Spanish which SPC Guillén translated as a solicitation for her to participate in a 'threesome.'" 

Afterward, another supervisor noticed "a marked change in her demeanor" after the incident, "which prompted the supervisor to ask if she was okay." 

Guillén then told her supervisor and another soldier what had happened.

"Between 16 September 2019 and 9 October 2019, two Soldiers reported this incident to her unit leadership, who failed to initiate an investigation," said the report.

Her supervisor was "unprofessional" and the behavior was "counterproductive" and "adversely effected SPC Guillén and others," investigators said. 

"This supervisor specifically targeted her, called her out in front of her peers, and consistently made an example out of her," said investigators. 

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The second incident happened during a field training exercise when the same supervisor "encountered SPC Guillén while she performed personal hygiene in the wood line and SPC Guillén reported that this made her uncomfortable." 

As a result of the findings, the Amy fired five officers and non-commissioned officers in Guillén's Third Cavalry Regiment and are taking unspecified administrative action against eight other officers. 

Since Guillén's death, her family has been pushing for federal legislation: The I Am Vanessa Guillén Act would create a new system for reporting and investigating sexual harassment and assault in the military, putting trained professionals outside an accuser's chain of command in charge. It would also change the way the military handles missing persons cases and give sexual assault survivors who are service members the right to make civil claims against the military. Currently, service members have no such recourse.

The bill is scheduled to be introduced on May 13.