The indictment came down on Tuesday, one month after a judge in Texas denied a motion requested by Cecily Aguilar, asking that her confession be thrown out.
The 11-count indictment includes charges of accessory after the fact, destruction of records in a federal case, conspiracy to tamper with documents and issuing false statements.
Aguilar was charged in July 2020 for her alleged role in Guillen's death. She was the girlfriend of the main suspect in Guillen's death, 20-year-old Aaron Robinson, an Army Specialist who was named a person of interest.
In March 2021, Aguilar asked a federal judge to toss her confession, saying it was taken illegally. Last month, a judge disagreed, saying she provided the information voluntarily.
According to federal court documents, officers did not read Aguilar her Miranda rights at the start of an interrogation that took place on June 30, 2020. The documents state Aguilar was being questioned about Robinson.
You can read all 27 pages of the court records here.
ABC13's Steve Campion was the only Houston reporter at her court appearance in Waco last month. For the first time, video of Aguilar's conversation with investigators was revealed.
The 22-year-old is seen on camera saying, "I'm ready to get this **** over with" before sitting down to speak with them.
Aguilar's public defenders have not spoken publicly about the case. Eyewitness News also learned that Aguilar told investigators Robinson forced her to participate in the crime saying he held a gun to her head and demanded her to go to the Leon River that evening in April.
Aguilar also claims her phone was taken away and that officers did not tell her anything she said could be held against her in court.
READ ALSO: Gruesome details in report show how Vanessa Guillen may have been killed
Aguilar reportedly helped lead law enforcement to Robinson, before he was confronted and killed himself.
WATCH: Suspect in Vanessa Guillen case had 'no remorse' in court, attorney says
Suspect in Vanessa Guillen case had 'no remorse' in court: attorney
If convicted, Aguilar faces up to 20 years in prison with a maximum $250,000 fine.
"I just watched that demeanor, I watched those tapes and I just realized, you know what? We're dealing with a very bad person here and hopefully, she'll get the punishment she deserves," said Guillen's family attorney, Natalie Khawam.
The video above is from a previous report.
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For updates on this story, follow Steve Campion on Facebook, Twitter and Instagram.