the honorable the united states court of appeals for the st circuit is now in session all persons having any business before this honorable court make give their attendance and they shall be heard god save the united states of america and this honorable court court is in session today's by extensive testimony and it was at times confusing and contradictory both sides presented starkly different versions of what happened in rwanda in one thousand nine hundred and forty as courts of long recognized expert testimony is uniquely powerful it was especially so in this case where the case hinged on credibility retest amount it was so varied contradictory and where so many of the witnesses came from a culture little context that the american jury would have had no found it can to understand the government began its case with dr clarke and even without naming mr to gunyah or any of the witnesses impermissibly commented on the credibility of the defense and bolster government witnesses in particular i'd like to focus on dr clarke's testimony about people of mixed hutu and tutsi descent in opening this or to go on you explained that his mother was tutsi and his father was hutu in response to the government's last questions on direct dr clark went far beyond saying that some people who participated in the genocide were of mixed ethnicity he said that this was a quote common defense for genocide suspects and he said that quote more often than not this defense had quote no evidentiary basis his testimony pinpointed mr to go on his defense associated it with something that genocide perpetrators often argued to avoid responsibility and acquired it not credible he did not need to  on his name his general testimony mirrored the specifics of what had been and would be presented by the defense this statement as well as the others highlighted in the briefing was inadmissible commented on the fence theory and you start the jury's wro what was the nature of the objection to it i don't know if there's a specific the government acknowledges that it's preserved the i go to the  and i do think that there are questions about whether or not dr clark had the ability to make that sort of broad pronouncement about him but that doesn't seem to be an objection you have brief but i but a but apart from that i think that  and you know the district court recognizes that if there's a part of the district court talks about the danger of having general expert testimony that then would allow the jury to leap to the specific and i think here it's there's no one else clark could be talking about there's no other reason to talk about people of mixed hutu and tutsi ethnicity other than that that that is what the defendant had just argued i beg your pardon i thought d clarke had in fact experience and interviewing a very large number of people and that that was the foundation on which he gave this testimony isn't that money did you say it's not their real evidence of this this testimony hinges on its connection to mr to go on his defense this testimony becomes relevant because mr to gone yet has just gotten up and said you know i am i am of mixed i am of mixed descent so it's clear that this testimony is being given to comment on that i'm sorry because it is relevant it has suddenly become the steps to monet about had a police officer testify about across racial identification a particular case saying why it should be impressed you know this was what he did and then you had an expert come and say well you know i've studied a lot of these as well so i'm just having trouble seeing how we would distinguish this from a whole variety of cases in which expert testimony comes to inform a jury about reasons to be skeptical about a certain type of testimony that when you st hear it might seem very powerful but you know what the context might start to see well maybe i should take it with a grain of salt i understand and i think here the defining principle comes when you look at what dr clark actually said i think if he had merely said there were some genocide perpetrators who were of mixed ethnicity i think that much could be ok but i think for him to come in and say you know i've interviewed what you know ten thousand two hundred however many genocide perpetrators and in in my opinion my expert opinion which is critical because it's about him being an expert this defense is not credible that's where i think the problem comes in is that he's commenting on what's been made clearly as a specific defense and he is targeting it and marking it as not credible child child sexual abuse case where the prosecution wants to put on a witness the witness says children often deny that they were abused for a whole variety of reasons so you can't really rest on the fact that the child denied it for ten years before wouldn't that be admissible and it sounds very similar to what we have here i think there's a difference between talking about saying that something happens something something that you might not expect staying that it happens and then dr clarke goes beyond that and says not only does this something that you might not expect to happen happens but in my expert opinion it is not a valid excuse it is not valid it's not ok which is what he did here is he says not only is this sort of defense that you might think that might immediate but initially sound ok to you not only is this defense not automatically true but it's also in my expert opinion not an acceptable defense not backed evidence that's the joy that part is the jury's decision to make what is backed up by evidence what is the evidence here and to evaluate the credibility of this person's use of that statement if i may move briefly to the sentencing more than a mere conflict in the trial testimony and i think that although that's not a perjury case i think that that background is very relevant to both of his preserved claims about the significant further obstruction and about the insufficient explanation  testimony by experts about whether confessions can be believed sometimes on the ground that the evidence is just that this may not be the objection that we have before us here but at the foundation for the experts  just can't support making it come in because you know i talked to i interviewed five hundred people next background and i found those five hundred people more often than not we're not telling the truth what value is that has evidence to for the jury to hear we don't know what the circumstance of those five hundred people were whether they're remotely like the person that we have here so i mean i can see a lot of reasons to be concerned about allowing this kind of testimony which is i talked to some people those people off and why i'm not saying this person is lying you should just know that's often the case but i could see a real reason for concern here i take it we don't have an objection on that score are intuitive to an american jury that that the testimony came necessary and at not only that it was necessary to flag the fact that this was a possibility that nd day that it was a possibility did make general objections and we would argue that those were that preserves these issues he made a general objection to the line of testimony about nick's ethnicities and he made a general objection to the imposition of the obstruction handsome and thus preserving the argument that like to say that there is the line thomas but this is also a unique case this is a case for mr to go on you have been pursuing asylum claims for twenty years if you went to trial it was seventeen days long he had put on one thousand witnesses say he was not this is not a case where he was the sole witness presenting a different narrative many people back up chunks of what he says and this is right return to the aca toy a language although the jury rejected that that is not enough and given th