The desecration of Arizkun Church and discovery of the Mairu-beso begin as a criminal investigation into violated sacred ground, but the burned infant bones found there acquire a far more intimate significance when DNA testing connects them to Amaia Salazar. The find joins local belief, the history of religious exclusion, forensic uncertainty, and a family secret that had been hidden for decades.

The Find and Its Forensic Meaning

The small bones had been burned at one end. Jonan Etxaide recognized them as a Mairu-beso, an infant bone believed to have particular powers if it came from a child who died before baptism. In older accounts, such a bone could protect its bearer; its smoke was also said to put the inhabitants of a house or even a whole village to sleep while the bearers carried out their misdeeds. The discovery therefore suggested more than a single desecrated church: investigators feared that a cemetery might have been violated as well.

The scientific examination established that the remains belonged to a boy at around nine months of prenatal development or about one month after birth. Although burned at one end, the bones were sufficiently preserved for testing. Doctor San Martín dated them to approximately 150 years earlier, with a margin of error of five years. That age appeared to fit the traditional account of a Mairu-beso, but the scientific result would soon unsettle the apparent distance between the find and the present.

The discovery also sat alongside a separate forensic question about cut forearms in the investigation. Doctor San Martín described a clean, post-mortem cut made with a toothed implement, possibly resembling a powered cutting tool, and noted a resemblance to the injury in the Johana Márquez case. Comparisons of photographs showed similar cuts on adult forearms, made by a right-handed person with comparable force and confidence. But the photographs could not establish that the same implement had been used, determine the bones’ age, or distinguish surgical amputation from grave desecration. Without the bone samples and the suspected tool, resemblance remained a lead, not proof that the cases shared an instrument or origin.

Local Belief and Historical Exclusion

The Mairu-beso’s supposed power depended on specific conditions in folk belief: the child had to be very young and unbaptized. San Martín explained that the category included a fetus, a miscarried child, or an infant who died at birth or in the first months of life. The belief drew force from the child’s imagined passage between worlds. In some traditions, a dead unbaptized child remained a protective presence in the family home; families might preserve its cradle, set a place for it at the table, or leave it food. The custom gave domestic form to grief, while also making the dead child’s continued presence subject to rules of respect and remembrance.

Jonan’s account of the Agotes supplied a different historical context for the church desecrations. Their origins were disputed: they might have been religious refugees, including Cathars; descendants of Gothic deserters who contracted leprosy; or a mixed population of outcasts brought to serve a local lord. They settled largely in Bozate and, for centuries, were barred from living elsewhere, running businesses, or marrying outside their group. They were restricted to trades associated with supposedly unclean work and marked by a badge on their clothing; in some accounts they also had to ring a bell to announce their presence.

Although the Agotes were Christians who observed Catholic rites, church practice reinforced their exclusion. They could be assigned a separate baptismal font, denied access to the altar, confined to the rear of the nave, and made to enter through a smaller door. At Arizkun, a grille once separated them from other worshippers; its removal reflected the shame that this history continued to cause among local residents. That history makes the church a charged setting for the desecrations, but the evidence does not establish it as their direct cause.

The DNA Match and the Family Secret

The laboratory result changed the case’s scale. Because the bones were well preserved inside, a routine DNA check produced a match: a 25 percent correspondence with Amaia. The result was repeated three times. After the first tests at Nasertic, samples were sent to laboratories in Zaragoza and San Sebastián, which returned the same finding. The investigators concluded that the remains belonged to one of her relatives, described as an ancestor in the fourth or fifth degree. Amaia’s immediate response was to question how a newborn from remains estimated to be roughly 150 years old could appear in a modern DNA database; the match was with a relative, not the infant’s own entry.

Later searches of family records brought the discovery closer to home. A birth register showed that Rosario Iturzaeta had had three deliveries: Flora in 1973, Rosaura in 1975, and, in 1980, a natural twin birth recorded as uncomplicated. The two girls were described as apparently healthy, but neither had a name entered. The record’s plain administrative wording stood in sharp contrast to what Amaia had been told about her family: the document disclosed another sister where family knowledge had contained none.

A separate death certificate recorded the newborn daughter of Juan Salazar and Rosario Iturzaeta as having died of “crib death,” the common term for sudden infant death syndrome. The certificate offered an official cause, but it did not settle what had happened. Family members said they had not known of the child’s birth; they remembered a closed coffin and had not insisted on seeing the infant. Amaia identified contradictions in the account of the death, irregularities in the birth certificate, and the unexplained infant bones as converging reasons for suspicion. Together, they point toward the possibility that the remains belonged to her twin sister, without resolving every circumstance of the child’s birth, death, or burial.

Consequences and Significance

The find links three kinds of evidence without making them interchangeable. Local tradition explains why an infant bone might be treated as a Mairu-beso; forensic testing establishes the remains’ developmental age and genetic connection to Amaia; family records reveal a twin birth and a death certificate whose account conflicts with the family’s silence. The historical exclusion of the Agotes gives the desecrated church an additional social resonance, but does not explain the DNA match or prove who disturbed the bones.

For Amaia, the investigation becomes an inquiry into the missing place in her own family as well as the desecration of a church. A bone initially approached as an archaeological or ritual object becomes evidence of an unacknowledged sibling. The mystery is not fully closed by the laboratory results: they establish kinship, while the records and recollections expose concealment and contradiction. The Mairu-beso thus stands at the boundary between communal belief and verifiable evidence, and between a publicly investigated crime and a private history that the family had left untold.