Given the existence of traumatic head injury and its neurological implications in past hate crimes against gay men - such as the appalling 1995 attack against Hawkes Bay man Jim Curtis - why has the defence of 'provocation' been allowed, and why did at least one case result in acquittal of the accused? I should note that this is a comment based on past incidents of homophobic violence. It will not specifically refer to ongoing courtcases, nor is it intended to do so. Given that hate crimes legislation focuses on hate-oriented cases of aggravated assault of specific individuals based on particular ascribed characteristics, what insights can neuroscience bring to these situations? I consulted a textbook on the subject to find out for myself. Fortunately, given advances in the discipline itself, survival rates have been enhanced, but there are questions of trauma counselling, rehabilitation and recovery for those who do manage to survive their ordeal. In the United States, males are most often the victims of traumatic head injury, mostly from serious falls, motor vehicle accidents and then violent assault, with sports injuries trailing the field. For that reason, I had to read selectively as well. According to applicable research, what happens when a fist, baseball bat, plank of wood or other rapidly moving object strikes the human head is skull fracture, as the energy of the object thrown produces what is known as a dynamic loaded injury impact on the bones of the skull, muscular and brain structures. Remember that the head is balanced atop a spinal column, and you can understand that load impact and recoil result in cases where the severity of the impact is insufficient to decapitate someone outright. In these cases, the head is thrown back with the force of the impact until it strikes furniture, walls or the floor. From the skull, fractured bone fragments may scatter inward, entering the neurons, synapses, bloodflow arteries and various compartments of the human brain. In addition to these intrusive fragments, neurochemistry will result in the sudden release of sodium, potassium or calcium, which will damage the cranial blood flow, resulting in obstruction of oxygen supply to the rest of the brain, or total cessation. These elements may also create the appearance of inflammation in skin around exposed skin outside the impact area/areas. Even in cases where victims survived, there may therefore be serious brain damage. Much depends on the severity of the impact when it comes to skull fractures. As well as intrusive bone fragments, the rest of the skull itself reverberates with the force of the impact, which may be sufficient enough to produce a cranial hematoma inside the brain. This will cause leakage of cerebrospinal fluids from within the brain and through the nose, mouth and/or ear. Contusions may also result, as the surface of the brain is roughly shoved toward bony outcrops at the base of the skull related to the eyes, nasal passages and mouth in some cases. There may also be percivascular bleeding, where blood seeps into the cerebral cortex and neuronic pathways of the brain. Even in cases where someone survives, memory, intellectual capacity and motor functions of the limbs may be permanently affected. In fatal cases, the impact may be sufficient to damage or obstruct continued brain functioning due to cumulative and widespread concentrated blood clotting and arterial congestion. What roles do forensic pathologists play in this process? Forensic pathologists are required to provide comprehensive evaluations of neurological damage from whatever cause is alleged to have led to the injuries or fatality under observation. In (US) trial settings, an adjudicating pathologist will inform the court of what injuries occurred, and how they are related to the observed injury or probable cause of death. In the context of (US) assault or motor vehicle accident negligence cases, applicable clinical studies, task force professional reports and official practice guidelines may also be produced as evidence. The pathologist is required to assess what is known as the proximate cause of injury or death. Based on the current status of medical knowledge and individual circumstances, she or he will then offer her professional assessment to the court. There will also be police incident reports to consider, which are often completed within standardised formats. Emergency departments may also produce valuable information from neuroimaging scans of internal brain injuries if the victim is still alive at the time of discovery of the traumatic incident. In cases of possible homicide, the pathologist follows a particular format. This will include the identified victim, describes the findings of the examination, and may include brain imaging data if available. The medical and psychiatric history of the deceased will also be considered if relevant to the assessment of severity of injuries. It should be noted that I am not a qualified neuroscientist or pathologist myself. This backgrounder should not be taken as an authoritative document about the forensic processes involved in New Zealand crime scence investigations related to the possible causal events described here. Source: Robert Granacher: Traumatic Brain Injury: Methods for Clinical and Forensic Neuropsychiatric Assessment: CRC Press: Roca Baton: 2003. Craig Young - 13th July 2007