Forensic Fridays

State of the art forensic techniques reveal evidence of interpersonal violence ca. 30,000 years ago

The Cioclovina calvaria, found in the Pestera Cioclovina cave of South Transylvania in 1941, is one of the few relatively well-preserved representatives of Europe’s earliest modern humans. The skull, dating back to about 33 thousand years from present, has two large fractures on the right side. For decades, researchers have debated the cause of these fractures, as the initial report by those who found it failed to document the cause of them, or even that they were present. Researchers have previously hypothesized that they were caused by explosions in the cave (which was a phosphate mine at the time), that the skull was mishandled by early researchers, that the cave collapsed, and even that the skull came from a victim of murder. Kranioti et al. (2019) wanted a more conclusive answer on the cause of the fractures, so they set out to find it themselves.

First, a computed tomography (CT) scan was performed on the skull to determine whether the fracture occurred ante- (before), peri- (during), or post- (after) mortem by looking for hints such as signs of healing and the shape of the fragments. Comparing the CT scan to the standard forensic criteria for timing of injuries, the researchers determined that the skull had been fractured during death (peri-mortem) — meaning the cause of the fracture was likely the reason for the person’s death. In addition, they found that the shape of the fracture was consistent with blunt force trauma, likely caused by a rounded object (such as a club or smoothed rock), and that the victim was likely facing their attacker at the time of the trauma. Unfortunately, as the only part of the skeleton recovered was the skull, we cannot know whether there are other injuries on the skeleton that are consistent with an attack with a blunt-object. However, the researchers concluded that based on their forensic investigation of the skull, the fractures were likely caused by a violent attack with a blunt object, and was likely the cause of this individual’s death.

If the cause of death was indeed homicide, it raises the interesting question of whether this was an inter- or intra-species conflict. Was it between two Homo sapiens? Or perhaps between a Homo sapien and an early species of human, such as Neanderthals? Hopefully advancements in technology and further evidence can help us solve this mystery!

If you’re interested in learning more about how modern forensic scientists solved a 33 thousand year old mystery, you can read the whole study here!

Kranioti, E. F., Grigorescu, D., & Harvati, K. (2019, July 3). State of the art forensic techniques reveal evidence of interpersonal violence ca. 30,000 years ago. Plos one, 17(7).

Eviction and Crime: A Neighborhood Analysis in Philadelphia

A new study by researchers at Rutger’s University and University of South Florida has found a positive correlation between the eviction rates in Philadelphia to the crime rates for 2006 to 2016. Currently, Philadelphia has the fourth highest eviction rate in the US, with about 1 in 17 renting households facing eviction.

The authors hypothesized that residential instability related to involuntary moves, like eviction, impact a communities overall crime rate more-so than housing instability characterized by voluntary moves. Eviction has also been associated with poverty, especially in already disadvantaged neighbourhoods. They further suggest that part of the reason for eviction-caused displacement increasing crime rates in neighbourhoods is due to the impact it has on a neighbourhood’s ability to develop a crime-prevention program.

To measure the relationship between eviction and crime, Semenza et al. (2021) compiled data from various sources, including each census tract in Philadelphia, the Philadelphia Police Department (PPD), the Eviction Lab at Princeton University, and the American Community Survey (ACS). The three crime statistics measured were the rates of homicide, robbery, and burglary.

The authors found that their hypothesis was supported, that neighbourhood eviction rates were directly associated with homicide, robbery, and burglary rates. Their study further supports the previous psychological and criminological literature that finds a direct correlation between poverty and crime rates.

Semenza, D. C., Stansfield R., Grosholz, J. M., & Link, N. W. (2021, August 3). Eviction and Crime: A Neighborhood Analysis in Philadelphia. Crime & Delinquency. 1 - 26.

French ex-officer's DNA ends 35-year murder hunt

Nicknamed “Le Grêlé” (meaning the pockmarked man), this killer was linked to four murders and six sexual assault cases against women spanning 1986 to 1994, although there is suspected to be more.

In a recent attempt to solve this cold case, in 2021 an investigating magistrate sent letters requesting DNA samples to 750 military police who were stationed in the Paris region at the time of these attacks. One of the men who received a letter was François Vérove.

Vérove was summoned by police on the 24th of September to provide a DNA sample, but he went unheard from. Just a few days later, on September 27, his wife reported him missing. Two days later on September 29, his body was found in a rented flat in a city if Southern France, along with a suicide note. In the note, Vérove suggested that he was the killer, and that he had “previous impulses” in the past, but “got himself together” when he married his wife and had children. His DNA was taken and found to match the unknown suspect DNA of the victims of Le Grêlé.

Vérove was a police officer and a gendarme, but recently retired within the past few years. Investigators when the crimes initially occurred suspected that the perpetrator was somehow involved with the police force or military due to the types of violence and tactics he used against his victims. It is even reported that he attempted to build trust with some of his victims by introducing himself as a policeman.

Thanks to the due diligence of the cold case investigators on this case over two decades after the initial crimes, the identity of the perpetrator has been identified, and hopefully can bring some justice, or at least relief, to the victims and their families.

French ex-officer's DNA ends 35-year murder hunt. (2021, October 1). BBC News.

Highly Stable, Nondestructive, and Simple Visualization of Latent Blood Fingerprints Based on Covalent Bonding Between the Fluorescent Conjugated Polymer and Proteins in Blood

Researchers have developed a polymer that binds to blood in a fingerprint to create high contrast images! And even better it doesn’t damage any DNA on the surface. Previously, dyes had been used but they were difficult to develop and didn’t work on all surfaces. This new polymer is absorbed into a cotton pad which is then placed on the prints (on any surface!!) and then peeled off after a few minutes to air dry. Each of the surfaces tested showed high contrast between the blood and the background under ultraviolet light. There was enough detail to distinguish whorls, short ridges, and sweat pores. Researchers then purposely contaminated the prints with mould and dust and they were still distinguishable. In one experiment, even a piece of DNA remained intact after being mixed with the polymer, which is huge for forensics as well.

Fan, Z., Zhang, C., Chen, J., Ma, R., Lu, Y., Wu, J. W., & Fan, L. J. (2021). Highly Stable, Nondestructive, and Simple Visualization of Latent Blood Fingerprints Based on Covalent Bonding Between the Fluorescent Conjugated Polymer and Proteins in Blood. ACS Applied Materials & Interfaces, 13(13), 15621-15632.

Fingerprint Found on Renaissance Wax Sculpture May Belong to Michaelangelo

Earlier this week at the Victoria and Albert Museum in London, employees made a shocking discovery: a fingerprint on a wax statue! They presume that this fingerprint belongs to Michelangelo as it was one of his statues. The fingerprint was found when the museum was closing due to the COVID-19 pandemic and the statue was being moved to a colder place in the museum. After five months in storage the staff were examining the statue to see how it had survived the heat and they found the tiny fingerprint on the statue’s butt. It has been suggested that the change in humidity and temperature has changed the wax’s composition making the fingerprint visible.

Davis-Marks, I. (2021, July 15). Fingerprint Found on Renaissance Wax Sculpture May Belong to Michaelangelo. Smithsonian Magazine. Retrieved from:

On the relevance of cocaine detection in a fingerprint

Did you know, scientists were able to distinguish between contact and ingestion of cocaine from a fingerprint. Both street cocaine and it’s powder in its primary metabolite (BZE) were used in the study.

Surprisingly, street cocaine was still present in fingerprints after washing hands, but BZE was no longer present.

They found that the detection of cocaine in fingerprints could show either ingestion of cocaine OR recent contact, but not both at the same time, and, anything over 48 hours after contact could no longer be detected through the fingerprints.

Considering the possible ethical guidelines that would need to followed with the use of cocaine in research, the dose was limited to 2 mg for health and safety reasons!

This discovery can possibly be used as a screening tool in the future!

Lang, M., Costa, C., Bunch, J., Gibson, B., Ismail, M., Palitsin, V., ... & Bailey M. J. (2020, February). On the relevance of cocaine detection in a fingerprint. Scientific Reports, 10(1), 1-7.

Diagnostics of skin features through 3D skin mapping based on electro-controlled deposition of conducting polymers onto metal-sebum modified surfaces and their possible applications in skin treatment

A team from Singapore has recently developed a device that can assess skin conditions and provide a 3D image in 10 minutes. Unlike other technologies, this portable device only weighs 100 grams and is battery operated, making it easy to transport to scenes if necessary. A 5x5cm gold coated film is pressed to a subject’s skin where the oils of the skin is transferred onto the film, creating an imprint. A bit of fancy science happens, creating a high-resolution 3D map of the skin.

Researches have used pig skin to map patterns of punctures, lacerations, abrasions, and incisions, using this device to obtain imaging of these wounds. It’s also said that it can be used to lift latent fingerprints and give a 3D image of the characteristics!

Fu, X., Cheong, Y. H., Ahamed, A., Zhou, C., Robert, C., Krikstolaityte, V., ... & Lisak, G. (2021). Diagnostics of skin features through 3D skin mapping based on electro-controlled deposition of conducting polymers onto metal-sebum modified surfaces and their possible applications in skin treatment. Analytica Chimica Acta, 1142, 84-98.