ORIGIN: In 1994, a student (belonging to a group of computer gamers and loners who were often bullied by popular and athletic students of the school) -- attending Columbine High School near Littleton, Colorado, USA -- was given a black duster (trench coat) as a gift from his mother, and wore it to school. Soon after, the student's friend started wearing a black trench coat as well, because he liked the style. And it wasn't long before the others followed suit. They wore the long coats even when weather was warm outside. It also wasn't long before jocks in the school started to ridicule the group by calling them "a trench coat mafia". After this, the group of friends took on the name and wore it like a badge, adopting the name for themselves, "The Trench Coat Mafia" (TCM) for short.

They wore all black and in attempts to fight back against the popular athletes and jocks in the school, the Trench Coat Mafia ridiculed the jocks right back, attempting to stand up against bullies in the school.

On April 20, 1999, two students who dressed like members in the TCM and were also bullied outcasts in the school, Eric Harris and Dylan Klebold (who had friends who were members of the TCM), planted two home made propane time bombs in the school's cafeteria, and went on a killing spree in the school, carrying one Hi-Point 995 carbine rifle, a sawed-off Savage Springfield pump-action shotgun, a sawed-off 12-gauge double barreled shotgun, and a TEC-DC9 semiautomatic pistol, along with numerous pipe bombs, grenades, smoke bombs, and knives. They killed twelve students and one teacher, and injured 24 other students, before committing simultaneous suicide.

After the shooting, often termed as the Columbine High School Massacre, the Trench Coat Mafia became an infamous icon against jocks and bullies, and catalyzed a movement of outcast students sending a message in schools across the USA (and spreading to Canada and the UK): "if you mess with us, we might just come to school one day, and kill everyone in it."

DEFINITION: A group of students in a school who are social outcasts (usually the target of bullying and called geeks, nerds, loners), who wear all black and often black trench coats, and express a disdain for jocks.
"Looks like the Trench Coat Mafia is on patrol today! Everyone run for your lives! They're pissed!"

Jock: "Those weird kids wear trench coats everyday, so they must be part of a Trench Coat Mafia, hahaha let's trip them up when they walk by and throw fecal matter on them in public hahaha."

Weird kid: *pulls out a shotgun and puts it in the jock's face and says "bang"*
by RagingTorrentialRain2 November 14, 2008
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A criminal and unconstitutional fabrication of what to profile pro and post Columbine Incident during the beginning of 1999, which is to single out "unwanted" elements of a State level school for "red flag" warnings of a possible second Incident. This criminal and blatant reckless disregard of profiling was divulged by the News media at large, from alleged FBI (Federal Level) information. The information was loosely pieced together at best and described the "red flags" of the profiled as "seemingly gothic, wearing black, usually wearing a black trench coat." They are usually singled out by peer pressure such as "jocks" and are normally bullied. 9 out of 10 of the profiled are not even suspected, and usually end up with harassment of death threats, vandalism, more bullying to the point of physicality due to panic and unwarranted and illegal harassment by law-enforcement officials. The Trench Coat Mafia is a red herring for misdirection and misinformation to say the least.
Trench Coat Mafia Red Herring FalsifyingUnconstitutionalFraudulent Peer PressureRed FlagsProfilingMediaMisdirectionMisinformation
by ThroatsDeep January 25, 2017
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A gang of goths. Originating in America they have spread to other countries, such as the UK. Unlike the Bloods and the Crips the Trench Coat Mafia are mainly suburban. As the name suggests the gang's colours are the black trench coats. The thing the TCM are most famous for is the 'High School Massacre' which happened in the 90's.
The Trench Coat Mafia were also known as 'the gothic movement'
by Blooddiamond21 August 31, 2007
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A gang of goths in which black trench coats are the colours. Unlike the bloods and the crips the Trench Coat Mafia are mainly based in the suburban areas. Even though they orginated in the America the TCM has started to spread to the UK and some of Europe. The most famous incident involving the TCM was in America in the 90's which was delicatly named 'The High School Massacre' in which they stormed a high school, heavily armed, took the head teacher hostage and killed students and teachers. Also called the gothic movement.
'Two people were convicted yesterday of attempted murder,they had ties to the Trench Coat Mafia'
by Blooddiamond21 September 8, 2007
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