The gunman visited the archaeological site repeatedly and appeared to act alone.

The man who killed one tourist at a Mexican pyramid and wounded several others had materials in his backpack tied to a 1999 U.S. attack, a possible reference to the Columbine High School massacre.

The gunman who killed a tourist and wounded several others at Mexico’s famous Teotihuacan ruins on Monday may have purposefully planned the date of the horrific terror attack for sickening reasons. April 20,

The gunman who opened fire at Mexico's Teotihuacan pyramid, killing a Canadian tourist, admired U.S. school shooters and Hitler, authorities said.

A gunman who killed one person and injured 13 others at Mexico’s Teotihuacán pyramids ranted about how much he hated tourists from Europe before opening fire.

While the gunman's presence did not initially raise any alarm, a commotion broke out when he supposedly started unpacking his bag. The tourists present there can be seen pacing down the steep ledges as gunshots ring out in the background.

A Canadian woman was killed in an attack from atop the Pyramid of the Moon that authorities have linked to the “Columbine effect”