Yes, corpses smell awful—but more careful scrutiny of that stench may help investigators learn just when a person died, the Royal Society of Chemistry reports. Apparently the trick is to measure volatile organic compounds (VOCs) like sulfurs, alcohols, and nitro compounds that change in combination and quantity as a body decomposes. So far an international research team has only done it with pig cadavers, but it's a start: "An odor fingerprint can be created for each stage of decomposition and possibly be used as an additional tool" to estimate time of death, or post-mortem interval (PMI), says study author Jean-Francois Focant. Other forensics experts have made progress trying to pin down PMI, phys.org reports:
- They've identified five or six bacteria often found in cadavers that may help estimate PMI. They want to create a kit "so that within two hours any crime lab or medical examiner's office can estimate" the time of death, says Baneshwar Singh, a forensic entomologist in Virginia.
- They've learned that certain bacteria could also reveal a body's race or ethnicity. Others attract or repel the black soldier fly to lay eggs in a cadaver.
- A Singh colleague worked on the Casey Anthony case, where investigators couldn't tell if a nasty smell indicated body decomposition or came from garbage in the back of a vehicle. Now Singh and others are trying to nail down the chemical composition of smells that come only from cadavers.
On the lighter side, chemist Raychelle Burks says a good zombie-repellant kit would include two "chemicals that smell really stinky": cadaverine and putrescine, which are used to train cadaver dogs, Mother Jones reports. "You could make up a death cologne" to trick zombies into thinking you're dead, she says on an Inquiring Minds podcast. (For more, read about a forensic expert's "secret fluid" for identifying corpses.)