The authorities in Mexico are still piecing together how a typical morning at the ancient pyramid complex of Teotihuacán, one of the country's foremost tourist destinations, descended into terrifying gun violence on Monday.

The video footage is disturbing. A gunman stands atop the imposing Pyramid of the Moon and opens fire on the tourists around him, who cower for cover among the pre-Hispanic stone structures.

After the ordeal, a 32-year-old Canadian woman had been killed and the gunman had died from a self-inflicted gun wound. Tourists from several nations, including Russia, Colombia and Brazil, were treated for their injuries in local hospitals.

The fact that visitors from overseas were targeted poses a headache for the government just weeks before Mexico co-hosts the men's football World Cup.

The shooting came less than two months after masked gunmen from the Jalisco New Generation Cartel unleashed a wave of violence, sowing fear across the country following the killing of their leader "El Mencho" by the security forces.

But this incident was very different.

Mexican authorities say the Teotihuacán gunman acted alone and there was no apparent link to Mexico's widespread cartel violence.

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".

Yet this is not solely about echoing US societal problems; Mexico's own issues with violence are partly at play, too.

The country experiences the constant mood music of drug-related cartel violence which Dr Villa believes has desensitised society and young people.

While guns are not as available over the counter or online with the same ease as in the US, weapons can be readily obtained on the black market.

Most of those guns have been smuggled into the country from the United States.

President Claudia Sheinbaum recently hailed the success of her federal security strategy - saying the daily homicide rate in February 2026 was 44% lower than at the end of her predecessor's term in September 2024.

She has also repeatedly argued that the country's murder rate had been stabilised by the last administration - led by her political mentor, Andrés Manuel López Obrador - and that it has been on a downward trend under her mandate.

Her critics argue the murder numbers do not tell the entire story of security in Mexico where, with tens of thousands of Mexicans unaccounted for, disappearances among young people remain a major problem.

President Sheinbaum was quick to offer her sympathies and "solidarity" with the victims and their families following Monday's attack at Teotihuacán.

The fact that the shooting at the popular tourist site came just a few weeks after the violence and havoc caused by gunmen from the Jalisco New Generation Cartel has caused real concern among football fans planning to come to the FIFA World Cup, which gets under way in Mexico City on 11 June.

The Sheinbaum Administration – and the president herself – are trying hard to reassure visitors that they will be safe and will take home with them only the fondest memories of Mexico, its people, its food and its culture.

Even though he appears to have been one deeply troubled man acting alone, the footage of a gunman on the Pyramid of the Moon firing at foreigners will not ease any fears, especially so close to kick off.