Forensic technology helps solving crimes in the Italian Alps
Updated: Dec 14, 2019
I like hiking in the mountains not only because of the breathtaking views and sceneries, but also because of the sense of peace and serenity that mountain brings inevitably. Being surrounded by nature is a fundamental need for most us, and research has even shown that nature promotes mental and physical health. However, as detailed in a previous blog entry (“Serial crimes in the Pyrenees”), mountains are not always the idealized picture, the haven of peace, we all have in mind. They can also be the scene of terrible events, including crimes.
Those events, which happened in 2015, were recently featured in the Forensic Magazine, following a publication by Dr. Francesca Davoli and her team detailing the method they used to solve the triple homicide.
The crime scene
It was a Sunday, in the Trento Autonomous Province. Michele Bruni was walking in a very dense forest area of the Italian Alps. The day before, on the 9th May 2015, she had heard very loud noises coming from the woods. What happened there? Were those noises from animals? From human beings? Moved by curiosity, she decided to explore the woods.
Suddenly, she found it. The first corpse. Small. A child. She called the authorities.
Dr. Francesca Davoli and her team intervened on the crime scene. They found a second corpse, close to the first one. Also small, also a child. Close examination of the remains revealed cruel injuries, atrocious mutilations and even partial consumption… by the murderer, or by an animal (bears are living in the region)? By a truly insane person, or a calculating perpetrator? Was the father of the children involved in the crime or was the perpetrator a complete stranger?
The Italian experts kept on inspecting the ground and discovered a third corpse. Much bigger, an adult, a female body, with many wounds and mutilations. The victim was covered with earth, branches and foliage: this time, the murderer tried to hide his crime. Immediately, the team thought they were facing a family tragedy: a mother and her two children were wiped off the face of the earth.
The scientists collected evidence on the crime scene. Trees had been broken, witnessing an intense struggle and suggesting that the mother had defended her children fiercely. “It is difficult to determine with certainty the dynamics of what happened, but it is clear that the struggle lasted for several minutes, during which the perpetrator repeatedly attacked [both the children and the mother]” noted Francesca Davoli and her colleagues.
To reconstruct the tragedy, identify the victims and trace the killer, hair samples were taken from all three corpses. In addition, saliva was collected through swabs on mother’s wounds, with the aim to isolate the DNA of the perpetrator.
A highly sophisticated forensic analysis
DNA was extracted from hairs and swabs. The samples were genotyped after PCR amplification of 15 autosomal microsatellite loci, allowing to obtain reliable genotypes from the three victims. Parentage analyses confirmed the relationship between the mother and her two children (a girl and a boy).
The difficulties started now. The four swabs showed the presence of only a very small amount of genetic material. They had to be handled and analyzed with care. The investigators used the open-source LRmix STUDIO software, designed to analyze forensic genetic profiles to solve their case. At first glance, the DNA recovered from the saliva swabs seemed to belong to the father of the children, but evidence on the crime scene pointed toward another scenario. The genetic material inherited from the father found on the mother actually belonged to the children. The killer must have injured the children and the mother alternately, contaminating the wounds with the blood of the young (containing genetic material inherited from the father). Through the LRmix STUDIO program, the alleles not belonging to the victims were isolated: they belonged to the culprit.
The perpetrator’s genotype was compared to those of the database, and there was a match. The Italian scientists have managed to give the killer a name, as he was registered in the database. The murderer of M33 (the baby boy), F22 (the baby girl) and BJ1 (the mother) was M7.
M7, what a strange name. It is because M7 is a male brown bear, part of the population that was re-introduced in central-eastern Italian Alps. This population comprises a total of 44 individuals (including the cubs-of-the –year), with a density of approximately 3.4 bears/100 km2 in the studied region. And all brown bear of Trentino are monitored.
Infanticide in bears is a male reproductive strategy where the killing of unrelated offspring induces premature estrus in mothers and increases the opportunity to breed with them. Resistance to infanticide may be costly: a female may sustain serious injuries in defending her offspring and sometimes the mother dies in an attempt to defend her cubs, as did BJ1. It has been observed that the death or disappearance of the dominant male (who is the father of the cubs) frequently coincide with an influx of younger immigrant males who contribute to infanticide. In isolated populations with a small number of reproductive adults, as for the Trentino population, infanticide can lead to population decline, especially in the case where the female is killed while protecting her cubs. Therefore infanticide can negatively impact the long-term conservation of the species and may need to be managed.
The killer has a famous grand-mother
M7 was not unknown. Neither was his grand-mother Daniza. M7 is the son of DJ3, who is the daughter of Daniza, a female brown bear transferred from Slovenia into the woodlands around Trentino in 2000. The fate of Daniza received quite a bit of media attention in 2014 after she sparked passionate debate about brown bear re-introduction in Italy.
Mid-August 2014, Daniele Maturi, a 38-year-old cable car worker, was looking for mushrooms near a small village in Trentino when he bumped into a female bear with two cubs. The man saw the animal 30 meters away and hid behind a tree to watch them. Unfortunately, Daniza spotted the observer and attacked him, to protect her cubs. The man managed to escape, with bites on his arm and knee, an injury to his back, and “40 or 50 stitches”. Daniza was then considered as a “dangerous animal”. The 18-year-old mother had a radio collar and was easy to locate.
During almost one month, local authorities tried, in vain, to capture her with traps set up with meat and honey. The aim was not to kill Daniza but to “home her in a fenced space”. At the end, mid-September, Daniza was shot with an anaesthetic… and died as the result of this intervention. The forestry police have opened an investigation into the unnecessary killing of an animal.
Finally, Daniza died all because she defended her two cubs… just as, one year later BJ1, had died because she defended her children against M7.
Mountains are not always peaceful
I love mountains for many reasons; one of them is the feeling of peace and tranquility. But mountains are also a life and death matter for many species, including ours. Next time I will be hiking in the Pyrenees, I will be thinking of these mothers who died protecting their cubs. The pyrenean population of brown bears has been estimated to 43 individuals. The chances to bump into one of them is close to zero because brown bears are shy and tend to stay away from humans. However, if I happen to see a bear, especially with cubs, I will keep in mind to not approach and not hide to watch them. I will just walk away slowly and quietly! I know that my behavior could put my health in danger… but also their life.
Publication by Dr. Francesca Davoli and her colleagues:
Infanticide in brown bear: a case-study in the Italian Alps – Genetic identification of perpetrator and implications in small populations. Francesca Davoli, Mario Cozzo, Fabio Angeli, Claudio Groff, Ettore Randi. 2018. Nature Conservation 25:55-75