MSPs are to look at whether violent criminals who have previously suffered a brain injury should have their condition taken into account by the justice system.
Holyrood’s justice committee is to take evidence on the issue after research by Glasgow University identified a link between crime and brain damage.
One in five killers is believed to have suffered a blow to the head.
However, there are concerns that some could manipulate any change in guidelines to secure a lighter sentence.
Scottish Conservative chief whip John Lamont said: “Analysing possible links between head injuries and crime is certainly a worthwhile exercise.
“But we would prefer that any evidence gathered could be used in a preventative way rather than in mitigation.
“The idea that a criminal could blame a spate of offences on a mystery head injury will worry the public, and the excuse would be blatantly open to abuse.”
The research carried out by the University of Glasgow has found a “significant association” between head injury and alcohol use, social deprivation and crime.
It called for more research into the link between head injury and crime, with a need to provide education and training about head injuries to NHS services and prisoners.
Peter McCabe, chief executive of brain injury association Headway, backed the Holyrood investigation.
“The majority who sustain a brain injury will not be involved with the criminal justice system,” he said.
“However, some of the effects of brain injury such as memory loss, increased impulsivity and reduced inhibition can lead people into difficulty with the law.
“At Headway we come across people who prior to sustaining their brain injuries have never committed a criminal offence and yet, for one reason or another, find themselves in police custody while trying to cope with the long-term effects.
“We must better identify brain injury at an early stage in the criminal justice system in order to ensure the correct course of action is taken. Rehabilitation can often be more effective than incarceration.”
The issue came before the Scottish courts a decade ago when siege gunman Malcolm McGougan’s lawyer said his client suffered a head injury in a road accident.
The Holyrood evidence session will look at the extent to which the criminal justice agencies and others work together to identify and mitigate the wider effects of brain injury and its impact in the criminal justice system.
It will also examine whether there have been changes following the transfer of prison healthcare to the NHS. The extent to which brain injury is taken into account as a mitigating factor in sentencing will also be looked at.
A spokeswoman for the Scottish Parliament said it would be up to members of the committee whether or not they want to extend the one-day evidence session into a full inquiry.
Anti-knife campaigner John Muir, whose son Damian was murdered in Greenock, said that victims of crime should also been seen by the committee.
“A brain injury is an explanation for why somebody has committed a crime, but it should not be mitigation for a reduction in sentence,” he added. “Victims of crime get a raw deal and this sounds like another raw deal getting put into position.”
Academics and practitioners will appear before MSPs on 12 August to be questioned about possible implications.