The US Supreme Court has stated a long time ago that for the law to be constitutional, it must be
- statutory (done by legislature and not by judges or executive/administrative agencies);
- be clear to an ordinary person (not university educated, no law degree); and
- contain a clear guide for application of the law for the police, prosecutors and judges.
What happens in court is usually the opposite. Lawyers and judges bamboozle the public with terms and "rules" that even judges and lawyers squabble over as to WTH they mean.
So, when I say "motion in limine", that is lawyerspeak for a good old request to the court not to allow introduction of certain proof at trial.
Now, I receive a lot of mail from readers of this blog who report that various prosecution-hired experts in CPS ("civil") and in criminal proceedings routinely testify in court on the so-called "ultimate issue" - was the defendant responsible for the injuries of the alleged victim or not.
Sometimes forensic proof (DNA evidence etc.) points clearly at the defendant, and then such testimony by the expert is warranted.
Oftentimes, though, a forensic expert LACKS proof (a person has been raped, but there is no DNA evidence pointing at the defendant as the perpetrator, or the alleged victim obviously died from a certain weapon - knife, gunshot wound etc.), and the expert fills in the gaps by testifying that IN HIS SCIENTIFIC OPINION it was the defendant who raped-stabbed-shot the alleged victim.
It is apparent that expert opinions are allowed in court only when an expert knows more than an ordinary person and can explain to the jury facts that the jury may not understand without an explanation from a person with specialized knowledge in a particular field.
Yet, once the expert testified that in his opinion the victim did have sex on the day of the supposed crime, or that the alleged victim did die from a stab wound or from a gunshot wound, if the expert does not have ADDITIONAL evidence pointing at the defendant as perpetrator of the crime, the expert no longer has specialized knowledge to inform the jury WHO DID IT - and his "opinion" on the matter should not be allowed.
In federal cases, while an opinion on the ultimate issue is not in itself objectionable, an opinion about the mental state of the defendant as to the ultimate issue (whether the defendant possessed the necessary criminal intent in committing the crime charged) is not allowed.
In New York State, the Court of Appeals (the top state court) has ruled that:
"In a sense, opinion testimony of an expert witness necessarily enters upon the jury's province, since the expert — and not the jury — draws conclusions from the facts, which the jury is then asked to adopt. Such testimony, however, is admissible where the conclusions to be drawn from the facts "depend upon professional or scientific knowledge or skill not within the range of ordinary training or intelligence." (Dougherty v Milliken, 163 N.Y. 527, 533; De Long v County of Erie, 60 N.Y.2d 296.)"
So, expert opinion on any issue of fact, and especially on the ultimate issue of defendant's guilt or innocence IS NOT ADMISSIBLE in court - and thus may and should be eliminated by a defense's motion before the trial - when an expert has made a prior claim (in any kind of a pretrial hearing) not based on evidence, but based on personal opinion of the expert that has nothing to do with any specialized skill or knowledge, that the defendant is guilty of committing the crime charged.
Defense attorneys often neglect making motions to specifically exclude testimony of prosecution's expert on the ultimate issue of criminal proceedings - whether the defendant committed the crime charged if the expert has no evidence of it other than the manner of death of the victim.
It must become a good defense practice to make such motions in limine/to exclude improper expert opinions.