Criminal: Last Meal

Nov 3, 2017

Botanists know all about plants, whether they're working in a forest or on a farm, but they can also identify plant matter after it's begun digesting. It turns out, that can be a pretty useful skill in solving murder cases. That's the topic on this week's Criminal podcast.

Host Phoebe Judge says there are lots of ways botany could be used to solve crimes, but this podcast explores the role plants play in food. Specifically, last meals.

Judge interviewed forensic botanist Jane Bock, who looks through the contents of a victim's stomach and see what's inside. Bock said the stomach is a little like an evidence locker.

"There's a valve that leads from stomach to the small intestine, and that valve snaps shut at death," Bock said.

Bock might not learn much from someone who filled up on marshmallows or hamburgers.

"With meat, you might say, 'Oh well they had a big steak.' Not if it's been in the stomach very long it just turns to gush because they don't have cell walls," said Bock.

That's because proteins break down, but the cell walls of plants remain visible under a microscope.

Bock mused: "They're just beautiful. To look at they're like little sculptures."

Plant cells can tell scientists what the victim ate for their last meal, and when they ate it. Bock and her assistants study the effects of digestion on plant matter by chewing up various foods and studying them under a microscope.

Judge said the timing of someone's last meal could prove or break an alibi. But, unlike DNA testing and toxicology, botany is not a common specialty in criminal investigations, even though it's a simple and cheap way to gather evidence. Bock lamented that not even the FBI's Quantico lab has a botanist on staff.

"They can do all sorts of wonderful things," said Bock. "I keep encountering them in cases, but they don't have any botanists. And I see them do things where they have a serious lapse of the treating of the crime scene or even of the victims when they ignore botany."

You can hear more about cases that were solved by studying what the victims ate on this week's Criminal podcast.

Criminal is recorded at WUNC.