A time-lapse chronology has revealed that decomposing bodies move, especially their arms, as they break down into their original elements, according to new research out of Australia.
The movements came to light after researcher Alyson Wilson used time-lapse photography to record the decomposition of a donor body in 30-minute intervals over 17 months, reported Australia’s ABC News.
The research took place at the Southern Hemisphere’s first-ever body farm, the Australian Facility for Taphonomic Experimental Research (AFTER), established three years ago just outside Sydney to help investigators decomposition as related to crime scenes.
Wilson, a medical science undergraduate at Central Queensland University, initially set up the time-lapse camera to test whether the equations governing decomposition in the Northern Hemisphere also held true in the south, according to ABC Australia.
In the Northern Hemisphere, “the climate is different, the weather is different and even the insects can be different," Wilson told ABC.
The photographic evidence indicated that the same equations held up on both sides of the Equator. That initial work was published in August in the journal Forensic Science International: Synergy.
But the photos also demonstrated something completely unexpected.
“What we found was that the arms were significantly moving,” Wilson said. “Arms that started off down beside the body ended up out to the side of the body.”
Xanthe Mallett, a forensic anthropologist and criminologist who also conducts research at AFTER and who supervised the study, said the observations caught everyone off guard.
“I was amazed when I saw it, especially how much the arms were moving,” the University of Newscastle lecturer told Vice Australia. “It was astounding.”
Sometimes the arms even moved back again to their original position, she said.
“We think the movements relate to the process of decomposition, as the body mummifies and the ligaments dry out,” Wilson told CQ University Australia, where she is an undergrad and working toward an eventual Ph.D in forensic anthropology. “This knowledge could be significant in unexplained death investigations.”
It’s significant because it tells forensic scientists that the position a body is found in is not necessarily the position a person died in, ABC said.
“What isn’t known is that the body moves as part of the decomposition process, and it’s the first time that it’s been captured, as far as I know,” Mallett said
“Being able to watch the human decomposition process in detail, as it happens, over time in 30-minute intervals will be invaluable in the search for better ways to establish time since death by determining when certain visible markers occur,” AFTER Deputy Director Maiken Ueland told ABC. “Knowing that body movement can result from the decomposition process rather than scavengers or original placement will be important when it comes to determining what happened, particularly if this movement is much greater than first believed.”