After weeks of searching, the woman's dismembered remains were found in June off base, buried near a lake and covered in cement.
Army officials would later say she was killed on base by a fellow soldier. Spc. Aaron Robinson allegedly hit her in the head with a hammer “multiple times” in an armory room at Fort Hood and partially dismembered her, authorities said. Robinson reportedly took her body to the Leon River, some 20 miles away, where he and his girlfriend at the time, Cecily Aguilar, buried Guillén’s remains, officials said.
Aguilar faces one federal count of tampering with evidence for allegedly helping Robinson dispose of Guillén's body. She has pleaded not guilty and is being held pending trial.
Robinson fatally shot himself as authorities tried to arrest him after Guillén's remains were discovered.
In September 2019, the soldier was sexually harassed by her superior when he asked her in Spanish to participate in a threesome, according to the investigation report. The second incident occurred a month later during a field exercise when the same superior approached her as she was washing her body, the report said.
“No evidence indicates that this sexual harassment was in any way related to her death,” the Army said in a press release.
The investigation concluded the supervisor was “unprofessional” and “created an intimidating, hostile environment” for Guillén and others, the report said.
The Army's handling of her disappearance and killing created national outrage, with relatives, friends, politicians and celebrities joining an online movement with the hashtag #IAmVanessaGuillen.
In December, a sweeping investigation of Fort Hood, which has the military's highest rates of violent assaults and homicides, found “major flaws” that left women “vulnerable and preyed upon, but fearful to report and be ostracized and re-victimized.”
Several bills have been introduced in Congress to change the way the military investigates allegations of sexual harassment and assault.
Natalie Khawam, an attorney representing the Guillén family, criticized the investigation, saying it took too long and did not adequately describe what happened to the soldier.
"We, the Guillén family and I, have found many inconsistencies in this report," Khawam said. "Vanessa’s case was severely mishandled. We are upset that there’s a lot of redactions and aren’t being provided the names, especially the soldiers that were sexually harassing her. It’s heartbreaking and frustrating for all of us. So many errors from commanders down," the attorney said in a statement.