This is a note from the two court experts (Pietro Pietrini, molecular neuroscientisit from the University of Pisa and Giuseppe Sartori, Cognitive Neuroscientist from the University of Padova) involved in the Bayout case in Italy. (see Nature news: ttp://www.nature.com/news/2009/091030/full/news.2009.1050.html)

No es mi culpa: son mis genes
Bad genes get a ligther sentence
Strafmilderung wegen "schlechter Gene"
The "DNA Pardon": Murder sentence genetically reduced
Un juge italien découvre le gène du meutre

These titles, used to summarise a decision from an Italian Criminal Court on a case of "diminuished capacity" due to psychiatric problems, are ill-posed and do not represent the core issue of this forensic case. Nowhere in our report or in the judge decision it is claimed a causal link between genes and criminal behaviour.

Dimisnuished responsibility was proved by a casual link (required by Italian criminal law) between a pathological mental state and and the criminal behaviour. The crime (homicide) resulted to be a symptom of the undelying psychiatric disorder. The defendant had a reduced capacity to "do otherwise" due to his mental illness.

Given that psychiatric symptoms may be easily faked as they are mostly based on the defendant's verbal report, the objectivisation of the "disease of the mind" is therefore critical.
Evidence that the psychiatric phenomenology causally linked to the crime has a "hard" neural basis was investigated using neuropsychological assessment, MRI and fMRI (using the stop-signal as activation task) and molecular genetics. Cognitive and molecular neurosciences aìwere not used to causally explain the crime but to insturmentally prove the "hard" correlates of themental illness wichi symtpoms are acusally linked to the crime.

We have found that the psychosis was also accompanied by other severe cognitive disorders, by a dysfunctional frontal lobe and a sfavorable genetics. We have assessed the defendant, previously evaluated only with a psychiatric interview, also with a full neuropsychological, imaging (morphological and functional) and genetic evaluation. The psychiatric interview may be may be easily faked by the defendant and it has a unsatisfacory inter-rated concordance. Neuroscience methods may, therefore, be used to better picture the "disease of mind" but can say nothing, contrary to what seems attributed to us, about the direct proximal causal link with the crime.The symptoms which, by incontrovertible evidence, are linked to the crime are a fully blown untreated psychotic state characterised by delusions of persecuzione, lowIQ, a very poor "theory of mind", and control of impulse. THESE ARE THE DIRECT CAUSES OF THE CRIME NOT THE BRAIN OR THE GENETIC.

In order to better characterise the required "disease of the mind" there is the legal requirement to show that the disease has a biological basis.Altered brain functioning in controlling behaviour and genetics are the required biological markers of the "disease of the mind". The only methods that can respond to this requirements are the methods of neuroscience that we have applied. THE CRITICAL ISSUE IS WHETHER THERE ARE BETTER TECHNIQUES, TO ADDRESS THIS ISSUES OTHER THAN THE ONE USED BY US? WE BELIEVE THE RESPONSE IS NO.

As regards to moleculasr genetics, we sequenced 5HTTLPR, STin2 – VNTR (Variable Number of Tandem Repeats) , rs4680, MAOA, DRD4-1/7. Results showed that for each of the examined genes the Defendant had one or both the alleles found to be significantly associated with aggressive and violent behavior.In our specific case, as I said above, for each of the candidate genes examined the subject had one or even both the alleles associated with a significantly greater risk for abnormal aggression, impulsivity and violence. This is a very sensitive issue and there is a need to be absolutely clear. To date there is NO indication of any DETERMINISTIC effect, that is, there is no genetic variant that determines abnormally aggressive behavior (no cause-effect relationship). What the studies reported in the literature have shown is that possessing one or more specific allele(s) is associated with a significantly greater probability of having abnormal aggressive behavior. That is, possessing such a variant is neither necessary nor sufficient to have abnormal aggressive behavior. However, the incidence of individuals with abnormal aggressive behavior is significantly greater in the group of people with such a variant than in the group without.

It is important to clarify that results from association studies have shown that possessing one or more of these genetic variants makes the individual more vulnerable to the effects of an unfavourable environment, such as childhood abuse and maltreatment or social exclusion (see for instance Caspi et al., Science, 2002; Eisenberger et al., Biol Psychiatry, 2006). Indeed, some of these environmental features were present in the case of our Proband.

In no way the conclusions reported in our evaluation of the defendant can be interpreted in a way that denies free will in favour of a genetic determinism (“I did not do it, my genes made me do it”, like a couple of newspaper titled). Indeed, our conclusion was based on the whole evaluation of the defendant, who showed a limited cognitive development (IQ= 70), a history of psychotic disorder with delusional ideation, a history of social exclusion, abnormal performance on cognitive testing for impulse control, abnormal pattern of brain activity in response to inhibition tasks and, finally, a genetic background associated with a statistically significant higher risk of impulsivity and aggressive behavior, especially in response to provocation. Considered each and all these pieces of evidence, we concluded that the defendant at a greatly diminished capacity, which is, by law, by law a mitigating factor.

Skeptics say that behavioral genetics studies are mostly based on correlations in groups of people so these data is hardly applicable to single individuals. This is false logic. Such a statement, infact, applies to every aspect of medical science. What I mean is that there is no test in medicine that has a sensitivity nor a specificity of 100%. Not even for a diagnosis of hyperglicemia you can rely on a clear-cut reference value, simply because what we call “normal reference values” are obtained through a statistical evaluation of data collected from hundreds of subjects. Thus, such objections are a too simple way to disguise the question. Data are data. In medicine, there is increasing evidence showing that having certain genetic variants increases the susceptibility to certain disease or may affect the likelihood to respond to specific drug treatment. Oncologists already take into account the genetic features of their patients in deciding for the best treatment strategy. In neuroscience, genetic and molecular studies are offering a powerful tool to understand the complex interaction between genetic characteristics and environmental factors in shaping our personality and behavior. This is with no doubt a great step forward. We need to avoid oversimplification as well as mystification. The titles of some news reports I read about this case around the world are simply misleading and untrue. In no way the conclusions reported in our evaluation of the defendant can be interpreted in a way that denies free will in favour of a genetic determinism (“I did not do it, my genes made me do it”, like a couple of newspaper titled). Indeed, our conclusion was based on the whole evaluation of the defendant, who showed a below normal cognitive efficiency (IQ= 70), a history of psychotic disorder with delusional ideation, a history of social exclusion, abnormal performance on cognitive testing for impulse control, abnormal pattern of brain activity in response to inhibition tasks and, finally, a genetic background associated with a statistically significant higher risk of impulsivity and aggressive behavior, especially in response to provocation. Considered each and all these pieces of evidence, we concluded that the defendant at a greatly diminished capacity, which is the requisite by law for a judge to cut the sentence.

The Court recognised all these further data as more convincing than a previous court evaluation based solely on the clinical interview and applied the maximum sentence reduction for "diminuished capacity". This further reduction was worth 8 months.