While this is interesting, it isn't really an improvement over traditional lie detector tests for a number of reasons despite contentions of those who insist that it works. Both technologies fail miserably when it comes to detecting lies, but that's not to say that brain scans aren't useful in a number of OTHER ways.
"Deliberately lying is hard work," Huizenga told VICE. "When you're telling the truth, you're just retrieving a memory. But when you lie you have to bring back the truth first and then manipulate it and doing that requires much more of the brain to be active. This means blood rushes to specific areas which are never really used when you're being truthful, and the fMRI allows us to detect these relative changes of blood flow."
The problem is that sometimes lies are simple and sometimes lies are complicated. The same goes for the truth and so when things are complicated the conclusion will always be GUILTY and when the situation is simple the conclusion will always be INNOCENT. There are other confounding variables to consider such as anxiety about whether or not the story is believable (true or not) and a host of other possible factors. So it seems obvious that this technology will never be appropriate for a court of law and should never be used to determine anything of importance.
LINK: https://www.vice.com/read/are-brain-scans-the-future-of-murder-trials-456