Scientific evidence has had its place in courtrooms for many years now in the form of fingerprints and DNA analysis among many others. As science is progressing at such a rapid rate, the legal system has the difficult task of balancing the use of new developments that could help make the truth more clear, and making sure that these techniques are valid and don’t violate human rights set forth by the courts. This is especially true in the realm of neuroscience. In his recent article “Can’t get you out of my head: The human rights implications of using brain scans as criminal evidence” (Farrell 2010), Brian Farrell discusses what evidence neuroscience can offer to the legal system by way of brain scans and how this possibly could violate legal human rights in two ways. Neuroscientists are experimenting with using fMRI and EEG as a sort of lie detectors to tell if someone has experiential knowledge of a crime that only the person who committed the crime could know. This can be done in several ways such as the traditional lie detector yes/no questions, simply showing images or reading statements with the subject passively perceiving, or presenting these stimuli so quickly they cannot be processed consciously. Then, a scientist can examine the locations of activation in the fMRI or the pattern of activation in the EEG to infer whether the subject had knowledge of each of the stimuli presented. In theory, introducing this kind of evidence would be the same as a recording of the defendant saying a specific detail during an interview that was not provided and could not have been known unless he was the perpetrator.

Farrell raises two ways that this kind of evidence could violate rights set by the legal system. The first is that, for at least the near future, the validity of these types of measures will be questioned. The process requires interpretation of scans which is always prone to bias or human error. If this type of evidence becomes admissible before it is definitely scientifically valid (and who decides what this means?), it violates a person’s right to a fair trial, according to Farrell. But even if everyone agrees that this process has become perfected, there is still another possible violation. It is likely that prosecutors will want to acquire scans of all defendants, and they might be allowed to without consent. However, if a scan is used against a person who did not consent, this could be seen as a violation of the guarantee against self-incrimination, which is an internationally guaranteed right, although what is counted in this has a few stipulations. The European Court of Human Rights says that fingerprints, urine, blood, etc. can be taken without consent as they have “an existence independent of the will of the suspect”. However, they also say that a defendant cannot be forced to disclose incriminating documents. So the question is whether these brain scans fit in with the first type or evidence or the second, and Farrell argues for the latter. First, he claims that a person’s memory and thoughts “should be viewed as a part of the person’s will” which makes these scans not meet the criterion that allows the other physical evidence. He goes on to say that the formation of memories is more than a physical process but “is a product of subjective interpretation and individual cognitive limitations.” In this way, he argues, these brain scans are like the documents that defendants cannot be forced to disclose. I think this second possible violation is interesting and one that the court is going to have to really think about before allowing this new type of evidence, even once is gets some scientific backing in the way of validity. Science in law is supposed to help us make fewer mistakes in courts and be more confident in the decisions that are made, but these improvements don’t seem worth it if our human rights are violated in the process.