Keep in mind that Fe judgement is objective while Fi is subjective. In legal case, judge seeks justice, and tries to arrive at a verdict, by collecting evidences and hearing witnesses. Regardless what a subject might think or feel, in the end it is the Evidences and witnesses that will be used as a basis of a verdict and they are usually sensory sensatible facts: fingerprint, document,etc, which are perceivable by the five senses and a verdict is a kind of a judgement whether the defendant is guilty or not with sentence that follows.
As far as I know, Judge duty of the trial is limited only until to arrive at verdict based on evidence collected and presented in the trial, but the real execution is undertaken not by the judge on his /her own, so Judge doesn't get himself/herself involved in the actual execution of the sentence he/she verdicts. For example, A judge that sentenced to death a murderer by hanging won't be executing the hanging by herself/himself. Since then, typologically, Judge is more naturally performed by Si primary and Fe auxiliary (ISFJ). Si is their primary, since in a trial, they are collecting a lot of past sensory informations (si)to arrive at a verdict (fe), but not executing the sentence themselves.
Remember that it is Si functions is more natural psychological function as in the trial the character of factual sensory information is past sensory information which is any information when the legal case happened,e.g a murder trial held for a murder event that happened one month ago, not Se as at the moment sensory information, like just imagine a murder was happening now in the court, what would be the device being used to kill, who was going to kill, who was the victim, how the murderer was using the device, etc.
Fe naturally feel someone is guilty also and it is the they strive to achieve in a trial. Even without becoming a judge, it is Fe type who frequently naturally blames others, anyway. I would like to say that verdict is psychologically a guilt feeling judgement institutionalized and formalized and further followed up by legal punishment to the defendant verdicted to be guilty and SiFe type will satisfyingly express their blaming habit and their guilt feeling judgement to an institutionalized legal practice.