Later that evening around 8:30pm, authorities re-interviewed Cecily Anne Aguilar, a local area woman who was the estranged wife of a soldier at Fort Hood. Aguilar was reported to be the girlfriend of Aaron David Robinson, a junior enlisted soldier. Robinson was one of the last known people to see Guillén on the day of her disappearance and had previously been interviewed by authorities in the case, where he’d stated their contact that day was about equipment she was working on. Aguilar told police that Robinson told her about killing a female soldier on Fort Hood. At the request of law enforcement, Aguilar placed a controlled telephone call to Robinson, who said "baby they found pieces" and texted Aguilar multiple news articles, to which he never denied anything in response. According to a criminal complaint filed in the Western District Court of Texas, Aguilar allegedly helped Robinson dismember and dispose of Guillén's body on April 22, 2020, after Robinson told her he had bludgeoned Guillén to death with a hammer inside the Armory in which he worked.