Can neuroscience
aid the legal system?
aid the legal system?
Brain Imaging and Criminal Law
May 04, 2009
by Astrid Fiano, DOTmed News Writer
MacArthur Law and Neuroscience Project (LNP) out of the University of California, Santa Barbara, is an organization devoting serious research to the use of brain imaging in criminal law. Walter Sinnott-Armstrong, PhD, Co-Director of the LNP and Professor of Philosophy and Legal Studies at Dartmouth College, Hanover, NH, spoke to DOTmed about the goals of the Project and its research topics.
Prof. Sinnott-Armstrong explained that the project developed from the MacArthur Foundation seeking useful projects to pursue. Dr. Robert Sapolsky, Professor of Neurology and Neurological Sciences, at Stanford University, suggested that the criminal justice system was in need of reform, and neuroscience could help. The Foundation approached Professor Sinnott-Armstrong, along with Art Singer, and they put together an advisory board. Dr. Michael Gazzaniga, of the University of California, Santa Barbara (future Director of the Project), and Stephen Morse, Professor of Psychology and Law in Psychiatry from the University of Pennsylvania Law School (future Legal Director of the Project) were on the advisory board, and crucial to the successful proposal to the Foundation and inception of the project. The participants were motivated in part to use "good" neuroscience to aid the legal system and in part to avoid the influence of "bad" neuroscience in the courtroom.
Good vs. Bad
What can be considered a "bad" use of neuroscience? Professor Sinnott-Armstrong points out a recent case in India. A process involving EEGs, called the Brain Electrical Oscillations Signature test (BEOS) was developed by Champadi Raman Mukundan, an Indian neuroscientist and former director of the clinical psychology department of the National Institute of Mental Health and Neuro Sciences in Bangalore. The results of the process were used in court for a murder case in Pune, India. According to the International Herald-Tribune, the judge cited the scan as proof the defendant's brain held guilty knowledge concerning the crime. The defendant was sentenced to life in prison. However, current brain state and imaging technology does not yet appear to function at the level of reliability most legal systems demand.
Using inferences from neuroscience for legal conclusions raises a question at every step, Professor Sinnott-Armstrong points out. As an example, an imaging procedure might be good to detect a structural abnormality within the brain, such as a tumor, but how relevant is the procedure to a legal situation--what does it have to do with criminal responsibility? In other words, can we infer from the brain scan that the person couldn't control his or her actions due to that tumor?
Part of the challenge lies in functional brain mapping. Brain functions lie in multiple areas of the brain and appear to be subject to significant individual differences. Addicts will have different reactions to different drug cues, for example. Localized brain functions and mapping are very problematic in some cases. Professor Sinnott-Armstrong explains, "Some mapping is done very well and is very reliable. We know where vision and language areas are. However, mapping is very difficult and controversial for understanding intentions and the control of actions." In neuroscience studies of groups thus far, a functional map can be drawn from an average of the group, yet within that group each person has their own activation pattern, and therefore it becomes difficult to apply group analyses to an individual. While neuroscience mapping needs a baseline for comparison, challenges will arise concerning the makeup of that baseline and if it is the right baseline for a particular individual.
The Project is still deciding how to approach brain mapping and is considering a variety of techniques. One approach might be statistical algorithm pattern classifiers for an individual based upon his or her neuropatterns. Another method may be to look within the group data and see where the variations lie, to get a feel for the different patterns for more reliable inferences. People have different strategies for remembering. If the various patterns can be determined, there is a higher reliability as to what can be inferred about the individual scan. However, such use of brain imaging still has to take into account the particular subject and how he or she remembers. People's memories may be happy or sad, or other preexisting conditions may affect the outcomes of the imaging.
Some legal scholars, practitioners, judges, and scientists also worry that the introduction of brain images into a courtroom or trial setting results in greater prejudice than it adds in terms of probative value. Some believe that when a scientist testifies, he or she will automatically be believed; others feel that in a long trial such testimony will not have as much impact. The actual effect of scientific testimony on jurors is another issue that is being investigated. This is being studied by the MacArthur Law and Neuroscience Project through the use of actual past cases, cutting down the facts to around 500 words - using brain imaging with one group, and no brain image with another. The researchers hope to see if there is a notable difference in verdict. From there, the research will build up to the use of complex cases.
Current brain science cannot predict that an individual will commit a crime at a particular point in time, but it can predict behavior; for instance, predicting that a substance abuse addict will obtain drugs within a short time; or that a diagnosed psychopath may commit a crime within five years, based on statistics. Professor Sinnott-Armstrong notes that the use of brain imaging in forensics raises a question of ethics - whether it is fair for a society to penalize a person (for instance, in denying parole) because his life is severely challenged due to a brain disorder. Right now there are laws that already punish for past behavior - the "three strikes" laws, which were implemented because the lawmakers felt that persons who committed three felonies are particularly dangerous and will commit violent crimes again - but those are predictions that are not based on scientific principles. Part of the work in the Project is to use science for better methods of determining behavior. The group of participants is diverse in terms of background and views on the moral and ethical questions, including lawyers and psychologists, who use their expertise in hopes that their work will lead to policies both useful and fair.
Project Goals
Dr. Michael Gazzaniga, Director of the Project, also expanded upon the work of the Project for DOTmed. Dr. Gazzaniga explained that the Project hopes to accomplish significant research to aid those involved in the criminal justice system to better understand criminal behavior.
Dr. Gazzaniga explained that the Project is divided into two research networks. One is focused on the current application of neuroscience to law and in university settings. This is called the Network on Legal Decision Making. Through that network, researchers are conducting studies on prisoners, especially psychopaths, to test their moral reasoning. Dr. Gazzaniga also mentions that Dr. Scott Grafton, at UCSB, is preparing to utilize pattern classifiers to see if there are differences in the brain that can be recognized in psychopaths. Other projects are also moving forward. Dr. Gazzaniga indicates that research is being conducted into whether the categories of guilt and moral responsibility in the law match evolved, human categories of blame. The role of lie detection - especially through fMRI scanning - is being investigated. Finally, the Project is seeking to understand and reduce bias in jurors. All of these are described by Gazzaniga as "pilot projects" intended to test whether and to what degree neuroscience can inform the law.
The second research network Dr. Gazzaniga identifies as the Network on Criminal Responsibility. It is investigating the model of the human in the law and what neuroscience might add to or take away from that model. For example, he states that one project may investigate the role of early frontal lobe damage, including its impact on low social economic status. Another proposal Gazzaniga describes is investigating the ability of addicts to learn from recent mistakes and considering how that affects issues like criminal negligence and recklessness. Gazzaniga stated that other proposals are forthcoming in what is now the second of three years in the initial grant.
In response to whether the research can lead to developing more convincing evidence in evaluations, trials and sentencing for criminal law, Dr. Gazzaniga said, "Neuroscience may assist in providing more convincing evidence. Under the Federal Rules of Evidence, however, whether evidence is convincing is not the test." He points to the role of the judge, as gatekeeper for scientific evidence, who determines whether the probative value of evidence is substantially outweighed by its prejudicial effect. As mentioned above, Gazzaniga reiterated that the Law and Neuroscience Project is investigating the impact of imaging evidence on potential jurors.
Finally, in considering how brain imaging (MRI, CT, PET, EEG) may demonstrate a malfunction in cognition that might be applicable to a defense, Dr. Gazzaniga explained, "We are investigating the widespread definitions of insanity and other 'excuses' in the law." When an excuse is found the defendant is usually excused from legal responsibility but placed in a mental or health care institution. He indicated that before we decide whether and to what extent brain images can show a malfunction in cognition applicable to a defense, excuse, or insanity, we must determine what we mean by stating that someone is not "responsible" for his or her actions. Brain imaging may, according to Gazzaniga, show differences in a defendant's brain that might eventually assist in determining an excuse in law. But, he warns, "we must always be on the lookout for our tendency to give too much weight to the idea that the 'brain made me do it' concept."
DOTmed also spoke with Don Rehkopf, an experienced criminal defense attorney in Rochester, NY, who has dealt with issues of brain imaging including MRI and CT scans in defense work. He also has co-authored a chapter in a graduate level neuropsychology text. "Almost all 'shaken baby' cases have multiple scans, as do assaults / homicides with head injuries or wounds." In how imaging is used and not used in criminal law, Attorney Rehkopf says, "I have been doing criminal defense work now for 33 years - neuroimaging is here, but only as a diagnostic or demonstrative form of evidence. There is no current use of it for "lie detecting" because it cannot [at least as of this stage and level of research] pass either the Daubert or Frye tests for reliability and thus, admissibility."
Rehkopf explained that there are no evidentiary challenges to brain imaging if one is versed and prepared with the laws of evidence. "First, the image must be relevant to something at issue in the trial - if the Defendant does not testify, his "truth" isn't at issue. Juries "see" better than they hear, so a blow-up of an image, showing particularized "damage" to an area of the brain, with a "normal" brain image next to it, is powerful proof. If you're a prosecutor and need to prove injury, or level of injury, or even sometimes "causation" e.g., "shaken baby" cases, that is very good evidence. But, it's also useful for the defense, e.g., the "injury" suspected may not be what the theory is. I had a case where the imaging showed that it was a blood clot from an unrelated surgery that caused the death, not getting hit in the head."
Rehkopf explained that the courtroom usages of such imaging is to show one (or more) of the following: (a) specific injuries to a part of the brain; (b) "bleeds" affecting larger areas of the brain; (c) swelling, to include compression of the brain stem; (d) other artifacts, e.g., clots, clogs or irregularities in development; (e) normal brain functioning, etc. "It is very useful in those cases where it is used to corroborate neuropsychological testing results."
In addition, Rehkopf notes that imaging is frequently used "as mitigation evidence in capital cases to demonstrate prior injuries, lack of development of key portions of the brain, tumors, etc. The key is linking it to conduct or reason and it is usually done in conjunction with a neuropsychological expert."
Recently in New York State, brain imaging was used in the defense of Peter Braunstein, who was convicted of kidnapping, sexual abuse, robbery, and other felonies in 2007, and sentenced to 18 years to life in prison. His defense attorneys used a brain scan to indicate his actions were due to mental illness. Rehkopf notes of the case, "His lawyers were taking a leap, which the prosecution's experts shoved down their throats that the imaging could "demonstrate" schizophrenia - but, there's no known correlation, just hypothesis. Besides, that case was not focusing on the "who did it" but rather, on an insanity defense, which is notoriously difficult to do in New York [and most places] post-Hinckley. I mean, his lawyers tried, but it was a long-shot from the very beginning. The concept requires acceptance of the hypothesis that there is a physiological aspect to insanity -- there could be as a result of injury or disease, but then you have to lay that foundation. It's a very rare case from my knowledge, primarily, at least in criminal cases, because of the Daubert issue. Braunstein's lawyers got around that by having the mental health people diagnose him, and then used the imaging as 'demonstrative' evidence to try and corroborate their diagnosis. But, his 'problem' was, as with most schizophrenics, he was lucid and rational at times."
At the moment, Rehkopf does not see any ethical issues in using brain imaging in law, "unless you get to the "truth/lie" function - that is still a hypothesis that medicine and science have not verified or confirmed to the level of general acceptance." However, Rehkopf is also critical of the Indian brain imaging/lie detector case. "The 'Indian' case is not at all about 'imaging' that uses electrical sensing to 'map' brain activity. It's a totally unproven process that depends on proprietary software developed by its inventor. It has been soundly criticized if not outright debunked."
Criminal defendants have long attempted to introduce brain scans to demonstrate lack of criminal responsibility, mitigation of sentence, and competency, with mixed success. A few typical cases on the subject include:
United States v. Erskine, 588 F.2d 721 (9th Cir. 1978). This case involved an appellant who sought review of his conviction on the grounds that the trial court should have allowed his medical doctor to testify (including using a brain scan) that he lacked the mental capacity to form the specific intent of his crime. In this case, the conviction was overturned and a new trial ordered.
People v. Weinstein, 156 Misc. 2d 34 (N.Y. 1992). In a New York State case of a man charged with second degree murder, the defense wanted to introduce the defendant's positron emission topography (PET) brain scan, as part of the defense that the defendant lacked criminal responsibility as the result of organic brain damage. The court held that the test was admissible.
State v. Marshall, 27 P.3d 192 (Wash. 2001) Here the defendant moved to withdraw a guilty plea for murder due to evidence of incompetency, including results from an MRI and EEG. The trial court denied the motion. The defendant appealed the conviction and death sentence. The defendant's guilty plea was vacated, the conviction was reversed, and the matter was remanded.
However...
State v. Zimmerman,166 Ariz. 325 (AZ Court of Appeals 1990) A criminal defendant appealed his conviction of first degree murder, arguing the trial court erred in excluding expert testimony as to a Brain Electrical Activity Mapping (BEAM) performed on defendant, showing there were abnormalities in the defendant's temporal lobe. The appellate court upheld the trial court's exclusion of the BEAM because it was not generally accepted in the neurological community.
People v. Chul Yum, 111 Cal. App. 4th 635 (Cal App 4th 2003) In this criminal appeal, the appellant argued that the trial court erred by not permitting evidence of his Single Photon Emission Computed Tomography (SPECT) brain scan showing post-traumatic stress disorder (PTSD). However, the appellate court ruled that the SPECT brain scan was not admissible to show the defendant suffered from PTSD, because the majority of qualified members in the neurology and brain imaging community did not support the use of the SPECT scans to diagnose mental disorders like PTSD and also considered the technique generally unreliable for that purpose.
Holland v. State, 705 So. 2d 307 (Supreme Court 1997) In a death penalty case on appeal, the appellant argued the trial court was in error for refusing a Computer Assisted Tomography (CAT) scan and a Magnetic Resonance Imaging (MRI) scan to determine brain damage. The court held that while a neurological examination would have been "helpful" for mitigation, the defendant didn't meet the established criteria for proving a substantial need for court to approve funds for such an expert.
Prof. Sinnott-Armstrong explained that the project developed from the MacArthur Foundation seeking useful projects to pursue. Dr. Robert Sapolsky, Professor of Neurology and Neurological Sciences, at Stanford University, suggested that the criminal justice system was in need of reform, and neuroscience could help. The Foundation approached Professor Sinnott-Armstrong, along with Art Singer, and they put together an advisory board. Dr. Michael Gazzaniga, of the University of California, Santa Barbara (future Director of the Project), and Stephen Morse, Professor of Psychology and Law in Psychiatry from the University of Pennsylvania Law School (future Legal Director of the Project) were on the advisory board, and crucial to the successful proposal to the Foundation and inception of the project. The participants were motivated in part to use "good" neuroscience to aid the legal system and in part to avoid the influence of "bad" neuroscience in the courtroom.
Good vs. Bad
What can be considered a "bad" use of neuroscience? Professor Sinnott-Armstrong points out a recent case in India. A process involving EEGs, called the Brain Electrical Oscillations Signature test (BEOS) was developed by Champadi Raman Mukundan, an Indian neuroscientist and former director of the clinical psychology department of the National Institute of Mental Health and Neuro Sciences in Bangalore. The results of the process were used in court for a murder case in Pune, India. According to the International Herald-Tribune, the judge cited the scan as proof the defendant's brain held guilty knowledge concerning the crime. The defendant was sentenced to life in prison. However, current brain state and imaging technology does not yet appear to function at the level of reliability most legal systems demand.
Using inferences from neuroscience for legal conclusions raises a question at every step, Professor Sinnott-Armstrong points out. As an example, an imaging procedure might be good to detect a structural abnormality within the brain, such as a tumor, but how relevant is the procedure to a legal situation--what does it have to do with criminal responsibility? In other words, can we infer from the brain scan that the person couldn't control his or her actions due to that tumor?
Part of the challenge lies in functional brain mapping. Brain functions lie in multiple areas of the brain and appear to be subject to significant individual differences. Addicts will have different reactions to different drug cues, for example. Localized brain functions and mapping are very problematic in some cases. Professor Sinnott-Armstrong explains, "Some mapping is done very well and is very reliable. We know where vision and language areas are. However, mapping is very difficult and controversial for understanding intentions and the control of actions." In neuroscience studies of groups thus far, a functional map can be drawn from an average of the group, yet within that group each person has their own activation pattern, and therefore it becomes difficult to apply group analyses to an individual. While neuroscience mapping needs a baseline for comparison, challenges will arise concerning the makeup of that baseline and if it is the right baseline for a particular individual.
The Project is still deciding how to approach brain mapping and is considering a variety of techniques. One approach might be statistical algorithm pattern classifiers for an individual based upon his or her neuropatterns. Another method may be to look within the group data and see where the variations lie, to get a feel for the different patterns for more reliable inferences. People have different strategies for remembering. If the various patterns can be determined, there is a higher reliability as to what can be inferred about the individual scan. However, such use of brain imaging still has to take into account the particular subject and how he or she remembers. People's memories may be happy or sad, or other preexisting conditions may affect the outcomes of the imaging.
Some legal scholars, practitioners, judges, and scientists also worry that the introduction of brain images into a courtroom or trial setting results in greater prejudice than it adds in terms of probative value. Some believe that when a scientist testifies, he or she will automatically be believed; others feel that in a long trial such testimony will not have as much impact. The actual effect of scientific testimony on jurors is another issue that is being investigated. This is being studied by the MacArthur Law and Neuroscience Project through the use of actual past cases, cutting down the facts to around 500 words - using brain imaging with one group, and no brain image with another. The researchers hope to see if there is a notable difference in verdict. From there, the research will build up to the use of complex cases.
Current brain science cannot predict that an individual will commit a crime at a particular point in time, but it can predict behavior; for instance, predicting that a substance abuse addict will obtain drugs within a short time; or that a diagnosed psychopath may commit a crime within five years, based on statistics. Professor Sinnott-Armstrong notes that the use of brain imaging in forensics raises a question of ethics - whether it is fair for a society to penalize a person (for instance, in denying parole) because his life is severely challenged due to a brain disorder. Right now there are laws that already punish for past behavior - the "three strikes" laws, which were implemented because the lawmakers felt that persons who committed three felonies are particularly dangerous and will commit violent crimes again - but those are predictions that are not based on scientific principles. Part of the work in the Project is to use science for better methods of determining behavior. The group of participants is diverse in terms of background and views on the moral and ethical questions, including lawyers and psychologists, who use their expertise in hopes that their work will lead to policies both useful and fair.
Project Goals
Dr. Michael Gazzaniga, Director of the Project, also expanded upon the work of the Project for DOTmed. Dr. Gazzaniga explained that the Project hopes to accomplish significant research to aid those involved in the criminal justice system to better understand criminal behavior.
Dr. Gazzaniga explained that the Project is divided into two research networks. One is focused on the current application of neuroscience to law and in university settings. This is called the Network on Legal Decision Making. Through that network, researchers are conducting studies on prisoners, especially psychopaths, to test their moral reasoning. Dr. Gazzaniga also mentions that Dr. Scott Grafton, at UCSB, is preparing to utilize pattern classifiers to see if there are differences in the brain that can be recognized in psychopaths. Other projects are also moving forward. Dr. Gazzaniga indicates that research is being conducted into whether the categories of guilt and moral responsibility in the law match evolved, human categories of blame. The role of lie detection - especially through fMRI scanning - is being investigated. Finally, the Project is seeking to understand and reduce bias in jurors. All of these are described by Gazzaniga as "pilot projects" intended to test whether and to what degree neuroscience can inform the law.
The second research network Dr. Gazzaniga identifies as the Network on Criminal Responsibility. It is investigating the model of the human in the law and what neuroscience might add to or take away from that model. For example, he states that one project may investigate the role of early frontal lobe damage, including its impact on low social economic status. Another proposal Gazzaniga describes is investigating the ability of addicts to learn from recent mistakes and considering how that affects issues like criminal negligence and recklessness. Gazzaniga stated that other proposals are forthcoming in what is now the second of three years in the initial grant.
In response to whether the research can lead to developing more convincing evidence in evaluations, trials and sentencing for criminal law, Dr. Gazzaniga said, "Neuroscience may assist in providing more convincing evidence. Under the Federal Rules of Evidence, however, whether evidence is convincing is not the test." He points to the role of the judge, as gatekeeper for scientific evidence, who determines whether the probative value of evidence is substantially outweighed by its prejudicial effect. As mentioned above, Gazzaniga reiterated that the Law and Neuroscience Project is investigating the impact of imaging evidence on potential jurors.
Finally, in considering how brain imaging (MRI, CT, PET, EEG) may demonstrate a malfunction in cognition that might be applicable to a defense, Dr. Gazzaniga explained, "We are investigating the widespread definitions of insanity and other 'excuses' in the law." When an excuse is found the defendant is usually excused from legal responsibility but placed in a mental or health care institution. He indicated that before we decide whether and to what extent brain images can show a malfunction in cognition applicable to a defense, excuse, or insanity, we must determine what we mean by stating that someone is not "responsible" for his or her actions. Brain imaging may, according to Gazzaniga, show differences in a defendant's brain that might eventually assist in determining an excuse in law. But, he warns, "we must always be on the lookout for our tendency to give too much weight to the idea that the 'brain made me do it' concept."
DOTmed also spoke with Don Rehkopf, an experienced criminal defense attorney in Rochester, NY, who has dealt with issues of brain imaging including MRI and CT scans in defense work. He also has co-authored a chapter in a graduate level neuropsychology text. "Almost all 'shaken baby' cases have multiple scans, as do assaults / homicides with head injuries or wounds." In how imaging is used and not used in criminal law, Attorney Rehkopf says, "I have been doing criminal defense work now for 33 years - neuroimaging is here, but only as a diagnostic or demonstrative form of evidence. There is no current use of it for "lie detecting" because it cannot [at least as of this stage and level of research] pass either the Daubert or Frye tests for reliability and thus, admissibility."
Rehkopf explained that there are no evidentiary challenges to brain imaging if one is versed and prepared with the laws of evidence. "First, the image must be relevant to something at issue in the trial - if the Defendant does not testify, his "truth" isn't at issue. Juries "see" better than they hear, so a blow-up of an image, showing particularized "damage" to an area of the brain, with a "normal" brain image next to it, is powerful proof. If you're a prosecutor and need to prove injury, or level of injury, or even sometimes "causation" e.g., "shaken baby" cases, that is very good evidence. But, it's also useful for the defense, e.g., the "injury" suspected may not be what the theory is. I had a case where the imaging showed that it was a blood clot from an unrelated surgery that caused the death, not getting hit in the head."
Rehkopf explained that the courtroom usages of such imaging is to show one (or more) of the following: (a) specific injuries to a part of the brain; (b) "bleeds" affecting larger areas of the brain; (c) swelling, to include compression of the brain stem; (d) other artifacts, e.g., clots, clogs or irregularities in development; (e) normal brain functioning, etc. "It is very useful in those cases where it is used to corroborate neuropsychological testing results."
In addition, Rehkopf notes that imaging is frequently used "as mitigation evidence in capital cases to demonstrate prior injuries, lack of development of key portions of the brain, tumors, etc. The key is linking it to conduct or reason and it is usually done in conjunction with a neuropsychological expert."
Recently in New York State, brain imaging was used in the defense of Peter Braunstein, who was convicted of kidnapping, sexual abuse, robbery, and other felonies in 2007, and sentenced to 18 years to life in prison. His defense attorneys used a brain scan to indicate his actions were due to mental illness. Rehkopf notes of the case, "His lawyers were taking a leap, which the prosecution's experts shoved down their throats that the imaging could "demonstrate" schizophrenia - but, there's no known correlation, just hypothesis. Besides, that case was not focusing on the "who did it" but rather, on an insanity defense, which is notoriously difficult to do in New York [and most places] post-Hinckley. I mean, his lawyers tried, but it was a long-shot from the very beginning. The concept requires acceptance of the hypothesis that there is a physiological aspect to insanity -- there could be as a result of injury or disease, but then you have to lay that foundation. It's a very rare case from my knowledge, primarily, at least in criminal cases, because of the Daubert issue. Braunstein's lawyers got around that by having the mental health people diagnose him, and then used the imaging as 'demonstrative' evidence to try and corroborate their diagnosis. But, his 'problem' was, as with most schizophrenics, he was lucid and rational at times."
At the moment, Rehkopf does not see any ethical issues in using brain imaging in law, "unless you get to the "truth/lie" function - that is still a hypothesis that medicine and science have not verified or confirmed to the level of general acceptance." However, Rehkopf is also critical of the Indian brain imaging/lie detector case. "The 'Indian' case is not at all about 'imaging' that uses electrical sensing to 'map' brain activity. It's a totally unproven process that depends on proprietary software developed by its inventor. It has been soundly criticized if not outright debunked."
Criminal defendants have long attempted to introduce brain scans to demonstrate lack of criminal responsibility, mitigation of sentence, and competency, with mixed success. A few typical cases on the subject include:
United States v. Erskine, 588 F.2d 721 (9th Cir. 1978). This case involved an appellant who sought review of his conviction on the grounds that the trial court should have allowed his medical doctor to testify (including using a brain scan) that he lacked the mental capacity to form the specific intent of his crime. In this case, the conviction was overturned and a new trial ordered.
People v. Weinstein, 156 Misc. 2d 34 (N.Y. 1992). In a New York State case of a man charged with second degree murder, the defense wanted to introduce the defendant's positron emission topography (PET) brain scan, as part of the defense that the defendant lacked criminal responsibility as the result of organic brain damage. The court held that the test was admissible.
State v. Marshall, 27 P.3d 192 (Wash. 2001) Here the defendant moved to withdraw a guilty plea for murder due to evidence of incompetency, including results from an MRI and EEG. The trial court denied the motion. The defendant appealed the conviction and death sentence. The defendant's guilty plea was vacated, the conviction was reversed, and the matter was remanded.
However...
State v. Zimmerman,166 Ariz. 325 (AZ Court of Appeals 1990) A criminal defendant appealed his conviction of first degree murder, arguing the trial court erred in excluding expert testimony as to a Brain Electrical Activity Mapping (BEAM) performed on defendant, showing there were abnormalities in the defendant's temporal lobe. The appellate court upheld the trial court's exclusion of the BEAM because it was not generally accepted in the neurological community.
People v. Chul Yum, 111 Cal. App. 4th 635 (Cal App 4th 2003) In this criminal appeal, the appellant argued that the trial court erred by not permitting evidence of his Single Photon Emission Computed Tomography (SPECT) brain scan showing post-traumatic stress disorder (PTSD). However, the appellate court ruled that the SPECT brain scan was not admissible to show the defendant suffered from PTSD, because the majority of qualified members in the neurology and brain imaging community did not support the use of the SPECT scans to diagnose mental disorders like PTSD and also considered the technique generally unreliable for that purpose.
Holland v. State, 705 So. 2d 307 (Supreme Court 1997) In a death penalty case on appeal, the appellant argued the trial court was in error for refusing a Computer Assisted Tomography (CAT) scan and a Magnetic Resonance Imaging (MRI) scan to determine brain damage. The court held that while a neurological examination would have been "helpful" for mitigation, the defendant didn't meet the established criteria for proving a substantial need for court to approve funds for such an expert.