The Liberator 3D printed plastic gun. Source: Defense Distributed
The Liberator 3D printed plastic gun. Source: Defense Distributed

In the hit CBS television series, Elementary, starring Jonny Lee Miller as Sherlock Holmes and Lucy Liu as Dr. Joan Watson, a 3D printed gun is used as a murder weapon in episode 1, season 2 that aired in January. Elementary is a contemporary retelling of the Sherlock Holmes series by Sir Arthur Conan Doyle and is set in the United States.’

While investigating a woman’s murder, Holmes and Watson discover evidence in the form of refrigerated milk that leads them to the suspect’s house, where Sherlock discovers a chipped nail. Sherlock comes to the conclusion that the gun was 3D printed in plastic and melted in acetone as a method of disposal.

Here are transcripts from the episode:

Sherlock: I don't believe it was milk in that bottle; I believe it was acetone.

Lestrade: He used acetone to melt the gun?

Sherlock: The crime, as I see it, Pendry shoots his wife at 6:33. He then disassembled his weapon and he dropped the pieces into a bottle he's filled with acetone. He then dials 999 at 6:36 to report that his wife has been murdered by an intruder. The acetone in the meanwhile is dissolving the gun he used to murder her, leaving nothing but a milk-like liquid in the bottle in his refrigerator.

Joan: It is illegal for a gun factory to make or manufacture a plastic weapon. But with advances in 3D printing, it makes it possible for anyone with the right specs to build one in the comfort of their own home. They only need one piece of metal to make it work: a nail to act as the firing pin.

Sherlock: Pendry couldn't very well melt a nail, so he hid it in plain sight. He used it to re-hang one of the masks in the living room before the police arrived. That's why it was hanging lower than the others - he did the work in a hurry. When I examined that nail today, I noticed that the tip was slightly charred. Carbon scoring from where it struck the bullet.

Sherlock and Joan go to a popular park with several security cameras and Sherlock holds up cue cards to asking local authorities to get him a list of people who have purchased 3 D printers. A few hours later, a list is dropped off.

Sherlock: I would wager that, like us, they (some of England's network of watchmen) are aware of the new and deadly advances in 3D printing. I would also wager that the nation's gun-averse and ever-more-paranoid security apparatus are tracking the sales of 3D printers.

3D printing technology has appeared in other popular television shows as well, such as CSI: NY, Big Bang Theory, and Futurama.

Watch Elementary