In a recent study conducted by scientists at the Institute of Environmental Science and Research in New Zealand and published in the International Journal of Legal Medicine, live pigs were shot in the head to study their blood-spatter patterns, according to The Independent. The pigs were shot with a Glock semi-automatic handgun from close range and the back-splatter of blood, bone and brain was subsequently analyzed.

Animals rights groups are calling the study unnecessarily violent and inhumane. People for the Ethical Treatment of Animals (PETA) says that mannequins or computer modeling would have given better results, making the experiment unnecessary.

"These incredibly violent experiments are entirely indefensible, given their cruelty, inapplicability to humans and the superior non-animal research methods that are available," said Justin Goodman, U.S. director of PETA's laboratory investigations.

Keith Bedford, the general manager responsible for forensic science activities at the New Zealand institute that conducted the study, said that animals were necessary to get the results that the study needed, according to The Guardian.

"It goes to the ability to provide reliable, and the most informative, evidence in a court case," he said. "It may be critical in protecting someone's liberty."

Bedford said that no future plans to carry out similar experiments are in the works, according to the National Post.