Army investigators said Friday that Army Spec. Vanessa Guillén, the soldier who was missing for more than two months before her remains were discovered in late June, could have faced some harassment some time before she was killed.

Guillén’s family say she confided in them that she faced sexual harassment before her disappearance on April 22 from Fort Hood in Texas, an allegation the Army said it has not substantiated. But investigators said on a call with reporters that she faced “potentially some harassment, not of a sexual nature.”

That potential harassment did not come from people of interest in the investigation, they said, or Spec. Aaron Robinson, the soldier they say killed Guillén before fatally shooting himself on July 1 in a confrontation with police. Officials did not say if that potential harassment was sexual or racial in nature.

Robinson became a “party of concern” April 28, six days after Guillén’s disappearance, according to investigators, and they were finalizing evidence of probable cause before Robinson left Fort Hood. “We don’t know the circumstances of his departure,” Undersecretary of the Army James E. McPherson told reporters on Friday.

Don Christensen, a former chief prosecutor for the Air Force, said an officer in Robinson’s chain of command could have held Robinson until the process was finalized, if they were alerted.

“They had no sense of urgency from the very beginning. Robinson early on was the most obvious suspect,” said Christensen, the president of Protect Our Defenders, an advocacy group focused on sexual harassment and assault in the military.

Guillén, 20, was bludgeoned to death at Fort Hood, near where she was last seen, investigators said. Guillén and Robinson each worked in arms rooms in nearby buildings, and investigators learned early on that Robinson was among the last witnesses to see her alive, he said.

Her disappearance, and her family’s allegations that she was sexually harassed, drew attention from activists, lawmakers, celebrities and other soldiers. Guillén felt she could not surface her allegations within her chain of command, her family said.

Army Secretary Ryan McCarthy said Friday he has directed an independent review of the command climate at Fort Hood in response to the killing.

Investigators defended what they described as a thorough investigation into Guillén’s disappearance and death amid questions from the family on whether the Army moved with enough urgency through more than two months of leads, when developments sometimes took weeks to unfold.

More than 50 law enforcement agents conducted hundreds of interviews and searched dozens of cars and phones, according to an Army official.

Investigators used cellphone data to track Robinson’s phone to a point near the Leon River east of Fort Hood, they said. On June 21, a burned-out section of ground and scorched trees were discovered, along with a smell of decomposition, an FBI agent wrote in a criminal complaint.

Agents and cadaver dogs did not find a body until nine days later when fence-builders nearby looked around after smelling the odor, investigators said. Her remains were discovered three feet from the burn site, said Tim Miller, director and founder of Texas EquuSearch, a nonprofit organization that assists in searches and helped on the Guillén case.

Agents unwittingly stood on top of her remains in their earlier search, Miller said.

Witnesses told investigators in May that they saw Robinson struggle with a large plastic box on the day of Guillén’s disappearance. Burned remains of a plastic box were found at the site, an investigator said, but he said it seemed of no value at the time.

Robinson’s alleged accomplice, the estranged wife of a former Fort Hood soldier, Cecily Aguilar, told investigators she arrived at the spot near the river to find Guillén’s body in the box before they dismembered, attempted to burn and buried her remains encased in concrete. Aguilar was arrested and charged with evidence tampering, authorities said.

After Guillén’s remains were discovered, Robinson “absconded” from his Fort Hood barracks, where he was on lockdown, the FBI said. An official said noncommissioned officers in the unit had “oversight” of Robinson but declined to address how or why Robinson was able to leave, or the nature of the lockdown.

Typically, soldiers are posted at all times at barracks entrances to monitor who comes and goes. Family attorney Natalie Khawam said she was told by investigators the lockdown was related to coronavirus restrictions.

It is not clear how many senior leaders were present.

Robinson fatally shot himself in Killeen outside Fort Hood after he was confronted by police in the early hours of July 1, the Army has said.

The Guillén family criticized the investigation’s progress, pointing to weeks of gaps before breakthroughs and perceived delays. They have called for congressional inquiries into Guillén’s chain of command and the handling of the investigation.

Guillén’s death also sparked calls by lawmakers to hold independent investigations and make changes in sexual harassment and assault policies in the military. Khawam said she will reveal proposed legislation on July 30 on Capitol Hill in Washington, timed ahead of a protest.