1. Retribution - nope; predisposition to crime doesn't change the appropriate retribution for the act;
2. Deterrence - nope; if we believe in deterrence then we definitely do not want people predisposed to crime to feel that they might get off lightly because of that; those people would be the prime "focus group" of deterrence that'd be threatened to keep their violent tendencies in check or suffer harsh consequences.
3. Rehabilitation - it depends; are the brain factors making you prone to violent behavior curable ? It might change the nature of appropriate punishment from imprisonment towards forcible curing = brain modification; but it's not really a mitigating factor there, more like an agravating one that requires more/different rehabilitation.
4. Incapacitation - it's an aggravating factor in that case; if you're genetically predisposed to violent crime, then according to incapacitation doctrine you should be isolated from society more/longer than someone who is less likely to reoffend.
5. Reparation - nope; no effect.
6. Denunciation - okay, for this theory it would be a mitigating factor. However, denunciation is generally applied to nonviolent crimes (ethics/morals issues); for murder generally we focus on combination deterrence, rehabilitation and incapacitation.
1. Retribution - nope; predisposition to crime doesn't change the appropriate retribution for the act;
2. Deterrence - nope; if we believe in deterrence then we definitely do not want people predisposed to crime to feel that they might get off lightly because of that; those people would be the prime "focus group" of deterrence that'd be threatened to keep their violent tendencies in check or suffer harsh consequences.
3. Rehabilitation - it depends; are the brain factors making you prone to violent behavior curable ? It might change the nature of appropriate punishment from imprisonment towards forcible curing = brain modification; but it's not really a mitigating factor there, more like an agravating one that requires more/different rehabilitation.
4. Incapacitation - it's an aggravating factor in that case; if you're genetically predisposed to violent crime, then according to incapacitation doctrine you should be isolated from society more/longer than someone who is less likely to reoffend.
5. Reparation - nope; no effect.
6. Denunciation - okay, for this theory it would be a mitigating factor. However, denunciation is generally applied to nonviolent crimes (ethics/morals issues); for murder generally we focus on combination deterrence, rehabilitation and incapacitation.