Investigators found Sánchez's fingerprints in the bathroom where the victim's body was discovered on October 3, 2025. Although the death was initially considered natural, an autopsy later confirmed the woman died from suffocation and suffered multiple injuries consistent with a violent attack.

Security cameras inside the apartment recorded Sánchez with the victim hours before the body was found. The clothing and jewelry seen in the footage match items later seized from her cell at Teixeiro prison, where she is serving time for three murders committed in Catalonia in 2006.

The suspect was on a temporary prison leave when the incident occurred. Forensic evidence and physical injuries found on Sánchez's hands further support the police theory that she was involved in the fatal struggle.