Multiple web search results confirm that a gunman killed a tourist and wounded several others at Teotihuacan on Monday. The claim regarding the purpose of the date is speculative and not directly confirmed by the evidence, but the core event is corroborated by multiple independent web sources.

Web search results confirm that April 20 marks the date of the Columbine High School massacre (April 20, 1999) and that the date is also associated with '4/20' celebrations. One web search result explicitly links this date to both the massacre and Hitler's birthday, corroborating the claim's components across multiple sources.

Two independent web search results report that the shooter, Julio César Jasso Ramirez, was reported to be a Nazi sympathizer and seen making the Heil Hitler salute, citing Telediario or Milenio as sources. This meets the requirement for corroboration from multiple independent sources reporting the same fact.

Multiple web search results confirm that the shooter left an AI-generated photo featuring him alongside Eric Harris and Dylan Klebold, the perpetrators of the 1999 Columbine High School massacre. This is reported by multiple independent web sources.

Web search results indicate that Ramirez was linked to the True Crime Community (TCC) and that this community glorifies school shootings, specifically mentioning Columbine. This is reported by multiple independent web sources.

Two independent web search results confirm that the attacker's t-shirt bore the slogan “Disconnect & Self-Destruct.” One source also links this slogan to the True Crime Community (TCC) and the Columbine shooters, corroborating the context of the claim.

Web search results confirm that the True Crime Community (TCC) is associated with the 1999 Columbine attackers and that its focus is on mass shootings and serial murderers, establishing the aesthetic link described in the claim.