Slashing pigs with swords doesn't sound like science. But that's exactly what scientists had volunteers do — hack away at a pig carcass with a Japanese samurai sword called a katana. [Read more about the stabbing study]
Actual murder cases inspired the study, said lead author Penny McCardle, a consultant forensic anthropologist to the Newcastle Department of Forensic Medicine in Australia. The cases involved victims slain by katanas. And the researchers wanted to figure out what types of wounds both these samurai swords and machetes would leave behind.
The scientists experimented on male juvenile domestic pig carcasses that they'd purchased from butchers. They packed the carcasses with Styrofoam packing peanuts to keep the internal cavities stable. Then, they hung them from from metal frames to simulate standing victims.
To look at the related cut marks, the researchers had volunteers wield a factory-made machete, a factory-made katana and a katana forged using traditional methods.
The scientists included the machete in their study because they realized it is a readily available tool throughout the world and often used in violent crime; even so, there is limited research on the resulting cut marks made by the machete.
The volunteers who used the factory-made weapons had no prior experience cutting or hacking with those weapons.
However, the person who wielded the traditional katana had 16 years of experience as a swordsman and performed expert slicing cuts.
By seeing the wounds on the pig carcasses, scientists could help investigators figure out what kinds of weapons were used in various murder cases.
After the volunteers hacked away at the carcass, the researchers examined the resulting cut marks on the pig's ribs, flat bones like the shoulder bone and long bones, such as the limbs.
They found that machetes created a unique cut mark called "chattering," or the breaking off of small chips of bone at the edges.
The katana, on the other hand, left unique marks on all three bone types — a tiny bit of curving by the bone away from the entry point of the cut.