Police in Mexico recently found a body that was burnt beyond recognition in a secluded patch of woods just off a country road.
According to NBC News, the victims hands and feet were missing, and there had been no physical evidence, of who the victim was, nearby except for a school graduation ring.
The burnt body was in such horrible shape that investigators could not even determine the gender of the victim. The only soft tissue available for genetic analysis was a burned fragment of liver, but attempts to get DNA profile from that small fragment proved to be a waste of time.
Forensic investigators did, however, find useful DNA samples in an unsual place, inside the guts of maggots that had infested the body’s neck and face.
“This is the first reported case of analysis of human DNA isolated from the gastrointestinal tract of maggots used to identify a victim in a criminal case,” researchers from Monterrey, Mexico wrote in a report this month in the Journal of Forensic Sciences.
A man claimed that his daughter had gone missing ten days before the body was found. When he looked at the burnt body, he recognized the ring, but couldn’t tell if the badly burned corpse was his daughter.
In order to determine whether or not it was his daughter, investigators took a DNA sample from the man and then looked at the gut contents of three blowfly maggots from the dead body. The researchers found traces of human DNA in the maggots’ stomachs.
With the DNA found in the maggots’ stomachs, the researchers were able to determine that the victim was female, and they were able to run a paternity test, which came back with a 99.68% match to the man, confirming that this was his abducted daughter.
Maggots are commonly used to develop timelines for crimes because the development of larva can indicate how long a victim has been dead.
Attracted by the gas escaping from a decomposing corpse, blowflies often appear within minutes of death, infesting parts of the body and laying their eggs there.
It’s the larva that are born from these eggs that serve as a timestamp. Depending on the temperature the larva can develop from egg to winged adult in a matter of 10 or so days.
But, in this case, the researchers were able to use this grim case to show how else the insects might be used as clues.
“If maggots are encountered in association with human remains, investigators could utilize this approach if the extraction of DNA from other sources is not possible,” wrote the researchers, led by Marta Ortega-Martínez, of Universidad Autónoma de Nuevo León.