He has been identified as 27-year-old Julio César Jasso Ramírez, a Mexican citizen who lived in Mexico City.
“The aggressor planned and carried out the attack on his own and there is absolutely no indication at this point that he had any external help or that any other individuals were involved in this incident,” said the Attorney-General of Mexico State José Luis Cervantes Martínez.
Among the gunman’s belongings, officials found a handgun, a bag of cartridges and a tactical knife.
But, the attorney-general added, they also found “literature, images, manuscripts apparently related to acts of violence which are known may have occurred in the United States in April 1999”.
A witness also told Reuters news agency that visitors had heard the attacker refer to Columbine – the site of a notorious US school shooting in which 13 people were killed by two teenagers on 20 April 1999, exactly 27 years prior.
Mexicans are no strangers to violence: some of the most atrocious massacres of this century in the Americas have been carried out on Mexican soil, generally between rival drug cartels fighting for territorial control.
However, the shooting at Teotihuacán appears to fall into a very different category altogether, that of mass killings carried out by lone assailants without apparent links to established criminal organisations.
Attorney-General Cervantes said that the evidence collected so far pointed to “a psychopathic profile of the attacker, characterised by a tendency to imitate situations that occurred in other places, at other times, and involving other individuals – this tendency can be referred to as copycat behaviour”.
The incident at the ancient site comes just three weeks after a teenager killed two teachers with an AR-15 assault rifle at his school in the western state of Michoacán.
Again, a profoundly unusual incident in Mexican society.
Valeria Villa, a Mexican family therapist with decades of experience in mental health issues in the country, described it as “a moment of transition, a very unfortunate, lamentable and worrying one, towards imitation of the phenomenon of mass killings we see every day in the United States”.
