The Board of Immigration Appeals has determined that “a key purpose of qualifying a witness as an expert is to provide a framework for the Immigration Judge to evaluate the evidence. In assessing whether to admit the testimony of a witness as an expert, an Immigration Judge should consider whether it is sufficiently relevant and reliable for the expert to offer an informed opinion.” “To be reliable, an expert’s testimony must be ‘based on sufficient facts or data’ that the expert ‘has been made aware of or personally observed’ or from sources that ‘experts in the particular field would reasonably rely on.’” “In considering how much weight to give an expert’s testimony, the Immigration Judge should assess how probative and persuasive the testimony is regarding key issues in dispute for which the testimony is being offered. However, to the extent that the record contains contradictory evidence, the Immigration Judge should explain why inferences made by the expert are reasonable and more persuasive than the other evidence presented.”
The full text of Matter of J-G-T- can be found here: