4.20.99 - The date that the attack at Columbine High School occured. This is also the date of Hitler's birth as well as a date associated with marijuana and drug use. It is also one day off of the anniversary of the Oklahoma City Bombing. As far as I can tell they never came right out and said "this is why we choose this specific date". There is also the possibility that it was originally scheduled for 4.21.99.
Dylan Follower - this speaks to the theory that Eric was the leader and Dylan was just a follower. I think this one has been disproved pretty well. Dylan's conduct during the events on 4.20.99 show that he wasn't following Erics orders and that he took the initiative to attack and kill some students. That being said, in every friend group there is always a person who is more extroverted and energetic and that was pretty clearly Eric. Dylan was depressed and I can easily see him being the "follower" among the two.
The Basement Tapes - These have almost become known culturally outside of the Columbine ecosystem. They are a series of tapes, mostly filmed in Eric's basement, where the two boys discuss the upcoming attack and their motives. They also discuss more than just the attacks including their lives and other events. They have never been publicly released by the government and with the dubious reason being they believe the videos will inspire similar shootings. While that may be true, I think that keeping them hidden has generated far more interest and intrigue among people who may not have cared otherwise. Some have said that the tapes have not been released because they would open Jeff Co up to additional lawsuits from victims families based on their contents. Jeff Co has also said that all copies of the tapes have been destroyed and that they no longer exist. This is almost certainly false as the tapes were digitized. Eric makes a prophetic comment when he predicts that the gov will only release small parts of their recordings in order to control the post attack narrative.
Columbine Movies - I'm not sure exactly what this is referencing but there have been a variety of popular and obscure films dealing with the events at Columbine. Bowling for Columbine and I am Not Afraid are the most commercially successful. There have been many lower budget films, even one filmed inside the school itself. My favorite Columbine related film is Zero Day. https://youtu.be/htjE6NIzgbA
Natural Selection/Wrath - (How Erics shirt probably looked) - (Actual image of Dylans shirt post death) These are the words that were printed on Eric and Dylan's shirts on 4/20/99. Eric's said NATURAL SELECTION and Dylan's said WRATH. They were both custom made at Custom Teez in the Southwest Plaza Mall (actual picture before it closed down). Dylan lists "buy wrath t-shirt" on his pre NBK to do list. Wrath is a song by KMFDM, a band that both of the boys liked (WRATH on YouTube). Hopefully someday we will get a high resolution image of the actual shirt Eric wore. I do believe that Eric saw himself as a force of natural selection, or, perhaps, his actions (whatever their surface level motivation) as a result of natural selection.
Hitler's Birthday - This goes back to the fact that Hitler's date of birth was 4.20 and NBK happened on 4.20. Eric did have a professed interest in Hitler and Nazism even going as far as to write a school paper on the subject and mentioning it multiple times in his diaries. I think it is possible that the thought was in their minds at some point, specifically Eric.
Harris Mastermind - Some people believe that Eric was the mastermind behind the entire plot and that Dylan just followed along. I do believe that Eric was more involved/obsessed with the planning and execution of the attacks but they were both equally involved on 4.20.99. I do think that if Eric had not been around that Dylan would not have perpetrated an attack while I am not so sure about Eric.
Shooting Was Failed Bombing - This is not really a conspiracy theory and is widely known. The plan of attack for NBK was to use large bombs to kill students during the lunch period and only use their weapons as a secondary attack to shoot at people trying to escape the building. The large bombs in the cafeteria failed to go off forcing Eric and Dylan to enter the school and start their attack. At one point you can even see Eric shooting at one of the bombs in an attempt to detonate it. Even though Columbine had wide ranging effects as it actually occurred, had their plan worked properly there would have been much more death and violence.
NBK - Not sure what the conspiracy theory is with this one. NBK stands for Natural Born Killers. It is a movie from 1994 staring Woody Harrelson where he is a mass murderer who is glorified by the media. We know that Eric and Dylan both liked this movie and they began to refer to their plans for Columbine as "NBK", probably just as an allusion to the movie and so they could refer to the attack without having others fully understand what they were talking about.
Columbine Memorial - There a couple of different columbine memorials. It started with a simple row of wooden crosses for the victims and one each for Eric and Dylan made by Greg Zanis, a carpenter from Illinois. There is now a permanent stone memorial in Clement Park next to Columbine High School. The only real conspiracy I can think of for this is the suggestion that Eric's cremated remains are actually buried under the stone where the ribbon crosses on the ground at the memorial. The other thing is that I remember back in 2021 some columbiners saying they were going to steal the donation box from the memorial. I guess they actually followed through because it went missing.
BlackJack Pizza - The local pizzeria where both Eric and Dylan worked. Eric and Dylan also filmed videos behind the restaurant including the "My Sisters Bike!" video. No clue what the conspiracy theory is here.
Columbine Books - There a slew of books pertaining to the events at Columbine. Many have been commercially successful such as "Columbine" by Dave Cullen and "No Easy Answers" by Brooks Brown. There are also a whole bunch of academic articles relating to the attack and also specifically about Eric. The books and papers vary greatly in accuracy and readability but I have found that they are all good reads as long as you approach everything skeptically. I guess the conspiracy here would be that the general corpus of books are trying to push a specific narrative.
Dave Cullen - Dave Cullen is an American journalist and non-fiction book writer. He wrote "Columbine" which has been the most commercially successful and popular book on the events at Columbine, including eight week son the NYT bestsellers list. While Cullen did years of research, many in the Columbine community have criticized the book and Cullen himself as promoting false narratives and incorrect information. He also blocked me on twitter so whatever.
acolumbinesite.com - a website that archives and displays a variety of information about Columbine. I have no idea who runs it and there are some dead links and the layout looks pretty old so my site is better.
The Trenchcoat Mafia - This was a group of students at Columbine High School who were into smoking and goth culture. Erik and Dylan got lumped into this group despite not really being members of it. The Media pushed this idea and it became part of popular culture. I firmly believe that neither Eric nor Dylan would ever have considered themselves to be a member of this group. My guess is it probably spread quickly because of other students at the school who didn't understand the group, or really know Eric and Dylan who may have seen them wearing trench coats at some point.
Bodies Left Overnight - The bodies at Columbine High School were not removed until 4.21.99 and remained in the school overnight while police properly secured the building and cleared it for explosives. It makes for some pretty erie photos from the night of 4.20.99. especially ones looking into the library because you know all of the bodies are just laying in there. The conspiracy theory is that the bodies had to be kept overnight because the Sheriff's office was changing things and setting the scene so things would look the way they wanted it to.
Reb and VoDKa - These are the nicknames of the two boys. Eric is Reb and Dylan was VoDKa. Eric used Reb as a moniker because it was the mascot of their school and because he was, in the truest sense, a rebel against the standard culture. He would often sign his diary entries with the moniker and would refer to himself by it when filming. I think there was a certain sense of irony in it for Eric, taking a nickname based on the school he planned to attack. Dylan used VoDKa because he supposedly enjoyed drinking vodka. Both of them have been theorized to have become alter egos for the boys as they got closer to the attacks. Some think it's possible that they saw the attack as being perpetrated by Reb and VoDKa and not Eric and Dylan. I don't really believe this. I think that Reb represented who Eric actually was including his real interests and ideas. He was forced to lie and cover up much of what he was planning and thinking especially in the months leading up to 4.20.99. Some of it may have been the type of person that he wanted the world to see him as. He was well aware that his writings would be read by many people.
E+D Suicide Photos - multiple photos of Eric and Dylan after they had killed themselves were leaked to the public. They are very graphic but provide a great insight into many things about that day. There is some debate as to whether the bodies are in the original positions or if they had been moved. I am almost certain they had already been moved. Jeff Co has said that the bomb squad came through before any crime scene photographers were allowed in and that the bodies had been checked for traps and explosives. The pictures really are tough to look at and it makes me sad everytime I do. While we don't know for sure who leaked the pics I think it was probably a victims family member who thought it would be good justice to the shooters... even though I think it probably backfired on them.
Police Didn't Enter for 3 Hours - The very first real knowledge of a shooting taking place at Columbine came into the Jeff Co Sheriffs dispatch at 11:25a when Deputy Neil Gardner, the community resource officer at Columbine High School is called to the backlot of the school and subsequently exchanges gunfire with Eric Harris. The dispatcher then reports possible shots fired at CHS. More units arrive as the situation becomes more clear. At 12:02p (maybe a minute before or after) the first SWAT team attempts to enter the school by using a commandeered fire truck to ram the doors at the North Hall entrance. So in reality the police tried to enter the building just half an hour after first contact and while still taking fire from the library windows. The maneuver didn't really work and only one part of the SWAT team got into the school building. There have been many criticisms of the police response and the timing of it. Part of the delayed entrance was due to the threat of more bombs and traps around the building. I don't see a conspiracy here. Just some mild incompetence. Eric and Dylan's bodies were found for the first time by the initial SWAT team entering the library at 3:23pm.
Rachel's Challenge - This is a school outreach program started by the family members of Rachel Scott, the first person killed in the attack. They preach about anti bullying and against gun violence. It is based on a code of ethics that Rachel wrote. I can't find any conspiracies relating to it and it seems to be a good organization with a good message... even if it is a little sappy for my tastes.