Mateo was a torturer and an executioner for the Spanish Inquisition. He was shaven bald and had dark brown eyes, as well as a scruffy beard. He usually wore a brown hooded cloak under a light brown leather apron with buckles. His clothes were stained and he sported several scars: two on his left cheek, one on his right cheek, one that ran diagonally across his nose, one across his left eyebrow, and an X-shaped scar on the right side of his forehead. At the time of his death, he had been stripped of his clothes and donned a scrapped brown tunic.
Mateo's body was found in the Spanish Inquisition's torture chamber, attached to a torture rack with his throat slit and multiple injuries on his body. After autopsying the body, Janis told the team that Mateo's killer had given him sleeping draught before tying him to the table and torturing him. Additionally, given the fact that the killer had tortured Mateo without puncturing any vital organs of him, Janis concluded that Mateo's killer had knowledge of anatomy.
Later, Jack and the player found a bloody sickle inside a bucket of rotten food. Suspecting that the killer had used the sickle to kill Mateo, the team gave it to Janis, who confirmed it to be the murder weapon. After analyzing the skin cells left on the sickle's handle, Janis confirmed that Mateo's killer was a woman.
Relationship with suspects
At the brothel, Mateo had crossed path with Grand Inquisitor Cardinal Cisneros, who clarified that he had gone there to weed out heretics and threatened to harm Mateo if he revealed his secret since he believed that he had not taken his word. His fiancée, maiden Isabel Vázquez, had no choice but to be engaged to Mateo as she needed a husband after the death of her father. Mateo also started getting wary of Inquisition healer Beatriz del Castillo, who was suspicious that he would discover her committing witchcraft. Escaped Inquisition prisoner Leonardo da Vinci was furious at Mateo since the latter had ripped the former's precious Mona Lisa painting in front of him. Mateo was also a client of prostitute Teresa Martínez, whom he treated badly, including hurting her with a spanking paddle.
Killer and motives
The killer turned out to be Isabel.
Admitting to the murder, Isabel told the team that Mateo had murdered her father after she rejected his proposal. Highly indebted after her father's death, Isabel needed a husband and reluctantly got engaged to Mateo, without knowing he was her father's killer until she overheard Mateo gloating about his actions. Deciding to make him pay with his life, Isabel laced Mateo's drink with sleeping drops and then tied him to a torture table, where she slashed his body several times with a sickle before slashing his throat. Understanding her crimes, Cisneros decided to excommunicate Isabel and quietly banish her from Spain.