Six U.S. citizens were among the wounded on Monday during a shooting at Mexico’s renowned Teotihuacán pyramids, a frequent stop for tourists.

Authorities in Mexico have identified the suspect as Julio César Jasso Ramírez. Officials claim he had visited the pyramids multiple times beforehand to scout out the exact spots he would later use for his attack.

The incident resulted in the death of one Canadian, while 13 others sustained injuries.

On Monday, a gunman opened fire at the historic Teotihuacan pyramids, as confirmed by officials.

In addition to the American victims, those injured include individuals from Russia, Brazil, the Netherlands, and Canada, according to reports from officials.

Regional law enforcement reported receiving initial notifications of the shooting at 11:20 a.m. local time. The National Guard swiftly arrived on the scene, with authorities noting that the assailant ended his own life by 11:45 a.m.

One tour guide who was at the scene told The Associated Press that the gunman fired upward.

“Some people, because they were scared … threw themselves face-down on the ground, and the rest of us started to go down,” the tour guide said.

The gunman carried materials related to the Columbine High School shooting. (Barak Hardley)

During a news conference on Tuesday, Mexican officials said they found “literature, images, and handwritten manuscripts, all allegedly related to violent events known to have occurred in the United States in April 1999” in the gunman’s backpack, referring to the Columbine High School shooting. That shooting took place on April 20, 1999.

Officials said the gunman was carrying 52 live rounds of .38 Special caliber ammunition inside a plastic bag, along with a knife.

Police and forensic workers stand on a pyramid after authorities said a gunman opened fire in Teotihuacan, Mexico, Monday, April 20, 2026. (AP Photo/Eduardo Verdugo)

Mexican President Claudia Sheinbaum addressed the shooting in a social media post on Monday.

“What happened today in Teotihuacán deeply pains us. I express my most sincere solidarity with the affected individuals and their families,” she wrote. “Yesterday’s attack highlights the urgent need to strengthen our security protocols.”

José Luis Cervantes Martínez, the attorney general of the state of Mexico, said that investigators built a “psychopathic profile” of the gunman, which was “characterized by a tendency to copy situations that occurred in other places, at other times and involving other figures.”

The Teotihuacán archaeological site will be closed until further notice after the shooting, the National Institute of Anthropology and History said in an announcement.