New York Lawyer's Legal Updates

Making Diamonds From Your Adversary's Coal

By Anthony J. Colleluori1

"A diamond is a lump of coal that did well under pressure." Lawyers who represent the indigent (or near indigent, which is worse) are often faced with a situation in which they cannot get the quality of experts they need to represent their client. This seeming negative, can be a positive, if we learn to listen to the expert the "other side" brings to the table and put those theories under pressure. In other words, by using the skills of friendly cross-examination2, and learning what we need to know to battle an expert in our case, we can bring about a double victory; we can use their expert to support our theory and at the same time, destroy the opposition's theory of the case.

Take for example a "diamond switch" case: Victim brings a diamond ring into a disreputable jewelry shop to have it cleaned. She is watching the procedure, but becomes distracted. She receives back a ring that has an "industrial diamond" in it worth approximately One Thousand ($1 000.00) Dollars as opposed to her actual diamond which had a value of over Ten Thousand ($10,000) Dollars. The technician, who cleaned the stone, is charged with making a switch and stealing the original gemstone.

In this case, the defense could not afford an expert and the court denied him a court appointed one3. The court mistakenly thought that the defense was going to argue that the value of the original diamond, less the value of the one received, would reduce the crime from an aggravated felony to a lesser crime. In preparing for the evaluation expert, Counsel uncovered gemological essays that taught the basics of gemstone "brilliance" (Brilliance is a gemological term of art that describes a gemstone's ability to "sparkle.")

Defense counsel chose not to reveal that the real reason it wanted to offer a gemologist was that the diamond could not have been switched by the technician that did the cleaning, as he never received the "expensive" diamond in the first place. Measurements recorded by the store owner on the work order, proved that either the owner, who originally received the gemstone, lied about what he received, or never received the diamond allegedly taken.

In preparation Defense counsel learned that measurements of the diamond's girdle, table crown size and depth, play a large part in determining the diamond's "grade". A review of the measurements for the diamond received for cleaning gave rise to the probability that the grade of the original diamond could not be the grade given to a diamond with the measurements recorded. Further investigation showed that this same jewelry shop had a similar "scandal" some five years prior. In that case the owner again put the onus for the "switch" on the technician who cleaned the diamond. That technician entered a plea bargain and pleaded out to a crime, an insurance policy covered the "loss."

The government's gemologist was a professor of geology and the original seller of the diamond to the victim; hence he had seen and evaluated both diamonds. (He was a colleague of the victim and sold her then fiance the ring ten years before.)

The expert was more than eminently qualified to render an opinion concerning diamond dimensions. There was no reason to believe he would be anything other than truthful about whether the recorded measurements would be able to yield a diamond that had the brilliance or fire of the one he originally sold, and in fact an review of his course syllabus showed he used two of the articles defense counsel read in preparation for his testimony. Hence the defense decided using this expert to prove the impossibility would bolster the defense's theory while undermining the theory of the adversary using the adversary's witness.

When the victim brought her diamond to the jewelry store, the shop owner measured the diamond and gave it a grade. The grade level was appropriate to the expensive diamond that was missing. The measurements recorded however would never have yielded the type of reflection expected in a ring with the brilliance and fire of the missing stone. The ring was then given to another salesperson who gave it to the technician. The technician began to clean the stone and setting provided. The diamond however had already been taken and switched (most likely by the store owner) and the diamond extracted from the setting by the technician was the industrial grade diamond. Further the setting was a "look alike" but not the original. The technician cleaned the diamond given to him and was then given the original setting to replace it in. Hours later, the victim, realizing the gem did not look like hers, reported the theft.

The Government used the gemologist to establish the value of the ring, however as often happens when counsel uses an expert witness, they overreached the qualifications. They qualified the gemologist as an expert not only on value but gemology in whole. It is not that the witness didn't qualify as an expert in gemology; it was just more than they needed him for, which allowed opposing counsel to use him for all of his qualifications. The party opposing the witness needs to set up the coming testimony. Using vior dire allegedly aimed at limiting the gemologist's qualifications, Counsel vior dire's the expert on his knowledge of the concepts of brilliance and refraction. Clearly the professor is an expert and the defense vior dire ends all question about the man's credentials when defense counsel agrees that the good Professor is indeed a well studied and well considered expert in the field of gems and their properties and value. The court then finds the professor to be an expert on both the properties and value of gemstones as well as an expert in gemology. The prevailing party cannot oppose his expert's qualifications, so they are stuck with the full qualification whether they need it or not.

The entire prosecution direct examination now runs toward evaluating the value of the gem that was stolen. The professor has long lost the dimensions of the original stone but he clearly remembers it being a near perfect and very rare diamond. It had nary a speck of carbon in it. The diamond that was exchanged for the victim's diamond was a carbon collection and the carbon was obviously viewable to the naked eye. Values for the two stones were then given and the prosecutor turned over the witness.

Cross of the Gemologist

The Defense had three goals with this witness;

  • Establish again for the jury what makes a diamond valuable;
  • Use hypotheticals to establish that certain dimensions (table size, crown angle, depth and girdle thickness) would not yield an "Ideal Cut" flawless diamond.
  • Establish the dimensions of the diamond as measured by the owner of the store and given to the defendant technician ;
  • Establish that the gemstone given to the technician could not possibly be the same as the one the expert sold to the victim some ten years before because the dimensions given would not permit the amount of refraction to yield the stone sold. In other words, whether the victim had switched the stone, or the owner had done it, the stone the owner measured could not have been the stone the witness sold.


  • Q: Professor, a diamond is valued by a rating is that correct?
  • A: yes
  • Q: That rating is determined by what is referred to as the 4 C's of diamonds?
  • A: that is roughly correct.
  • Q: I will get into that in a moment but let's talk about the 4 C's of Diamonds. That stands for Cut?
  • A: yes that is the first
  • Q: Clarity?
  • A: Yes
  • Q: Color
  • A: Yes
  • Q: and Carats?
  • A: Yes.

Now counsel has established that he knows a thing or two about diamonds, and is in control of the witness because he is asking distinct questions with very few words and is getting agreement from the witness.

As the examination goes on, counsel will go back to cut clarity and color and define each of these phrases, and will then ask if it were possible to have a diamond rated by this witness with the dimensions recorded by the Store owner in the case before us. The answer will be no because the stone described cannot have the brilliance or color of the stone the witness sold and rated so well.

  • Q: In order to have an "Ideal cut" stone, would you agree that there must be certain symmetry between the stone's: crown, pavilion, table and girdle?
  • A: Yes
  • Q: The stone that you sold Mrs. Brown had the 'ideal cut' symmetry of a 32.5° crown, 40° pavilion, 58% table and 1% girdle maintained.
  • A: Yes
  • Q: If the crown were say, 34 Degrees, the cut would not be considered "Ideal" right?
  • A: not really but it would be close.
  • Q: well what if the crown was say 38 degrees and had a pavilion of 32 degrees? That wouldn't be ideal would it?
  • A: That stone would not be an ideal cut.
  • Q: That stone could not have the level of "Brilliance" or "fire" that would be expected in an internally flawless or VVS Diamond with a D or F color grade would it?
  • A: Absolutely could not have that grade.
  • Q: That type of diamond would not yield the refraction that would make the colors brilliant.
  • A: That is absolutely correct!
  • Q: Please look at People's exhibit 2 in evidence; in your professional opinion would you agree that the stone measured in that document could not be the same stone you sold Ms. Brown 10 years ago?
  • A: Yes I would agree.
  • Q: In your professional opinion and within a degree of gemological certainty, is the stone described in People's 2 the same stone you sold to Mrs. Brown?
  • A: No It is cannot be the same stone, either the measurements were taken incorrectly or the stone recorded was not the one sold to Mrs. Brown.

In using the prosecutor's witness defense counsel added credibility to his theory because the witness is agreeing with the defense statements. One may argue that Defense counsel is also crediting the witness, but counsel would want this witness as his own if he could have afforded him. In fact under FRE 611(b), it is well within the discretion of the trial judge to allow this type of evidence even if it goes beyond the scope of the direct where it finds that to do so does not confuse the jury and serves the purpose of accommodating the needs of the expert. The proviso is that the defense must use direct questioning. In this situation however that is not a problem. The prosecution must also be permitted to use leading questions on areas of direct inquiry of the defense. See Lis v. Robert Packer Hospital 579 F.2d 819 (Third Cir. 1978.) One might argue that this cross however is not outside the scope of direct as gemstone grading is a large part of valuing a diamond. If counsel had been presented with an objection that the testimony was beyond the scope of the direct, counsel could switch to non leading questions or set up the testimony with relation to how it is part of the valuation testimony offered by the opposing party.

Advocates are rarely able to guess how an opponent will use their expert witnesses prior to putting the witness on the stand. Further unless the witness is going to disagree just because he is "their witness", it is equally unlikely that someone will guess that your vior dire is going to increase their credibility at the expense of the offering side's case.

Take for example a Murder case where the key issue is the distance of the muzzle of the weapon from the entry wound. There is no definitive testing done by the prosecution because: a) they know who did the crime and, b) they know why. The victim is without a weapon and their theory is that the killing was done in revenge for an earlier "street dis"4.

Early in the case the prosecution called the Crime Scene Investigation unit. Unlike the CSI guys on TV, this officer comes in to take pictures and collect evidence from the scene, but after processing same, the evidence is handed over to the lab which works with the lead detective and CSI does not direct or oversee the lab or investigatory portion of the science. In preparation for the trial, counsel speaks to the witness and learns that the witness is both garrulous and likeable. Counsel learns that the witness is not a ballistics expert but that wound entry is not only an area of expertise of a ballistics expert. It is clear from speaking to the witness that he is not happy being overlooked in the expert food chain and if given the chance would gladly give an opinion. In fact, he would agree with the defense position that the wound was a close entry wound.

When the prosecutor offers the witness as an expert in crime scene analysis. Counsel does not object and in fact on vior dire elicits that the CSI worker had worked on many gunshot cases (well over 300) and that he was required to take photos from various angles which meant (of course) that he had to know something about wound entry. He agreed and Defense counsel agreed that the man was an expert in crime scene investigation. Very scientific sounding. The court found the expert an "Expert in Crime Scene Investigation" ... whatever that means.

While on cross, defense counsel asked the witness if he would agree that a close range shot from a shotgun such as the one recovered here would be about 6 or less inches from muzzle to entry. The witness, being prepared by defense counsel for this testimony (as opposed to the Assistant District Attorney who offered him) to render such an opinion agreed as it seemed reasonable. Then Defense counsel elicits that the gunshot wound in the body of the deceased is in fact very tight indicating a close range shot. Again Defense counsel is suggesting the evidence and the findings, allowing the witness to either agree or disagree. The witness, really out of his league, agrees for fear of looking bad, and offering counsel is helpless to stop the cross unless he suggests the witness is not an expert as he offered him. Defense counsel elicits other actual facts like the height and weight of the decedent and then offered a hypothetical on how the bullet could have gone into the decedent in a downward manor if the defendant was shorter than the victim. When the government opposed the hypothetical, the court stated that the witness was an expert in crime scene investigation and could advance theories based on hypotheticals. Now had the Prosecutor objected to the hypothetical as going beyond the scope of direct, defense counsel must use the science of wound entry in helping the witness know what to photograph. Counsel also has the option of questioning the witness as if on direct. Either way, the big hurdle with this witness is already overcome because he has been qualified on the topic by the prosecution on its own case.

The Defense never attacked this witness, who clearly won over the jury with his manor and his "wisdom". Now the defendant did not have to call its own witness to establish the things established with this witness limiting the liability of offering a witness to cross and again turning the opposition's case on its head by "bolstering" the defendant's theory using the other side's expert.

As the case progressed, the prosecution called its "real" expert on shotgun blasts. That expert had only handled 5-10 shotgun wound cases and was disqualified as both cumulative (FRE 403) and because he did not take the required tests to see if the people's theory on muzzle to entry wound distance was correct (though he would have hazard an opinion that it was in fact a midrange muzzle to entry wound distance. It could have been argued then that this testimony would confuse the jury as the two prosecution "experts" differed in opinion on a crucial issue in the case.) Once he did not qualify to give the opinion, it left the opinion of the CSI officer, which supported the defense theory.

Remember that when cross-examining an expert, chances are they are not happy to come to court and do not want to even think about liking you. Hence your "creampuff" questions begin to align the witness with you. In fact he may like you more than the lawyer who called him who probably does not really know what the witness knows, beyond what the theory of the offering attorney's case is. Hence getting him a chance to qualify and be accepted by the others in the case as more of an expert than he may make him more likely to agree with you.

At the end of the Murder trial, the Assistant District Attorney was unable to point to any measurement that supported his mid-range gunshot theory, yet the defense could comment on the statements of the "other side's expert". The prosecutor couldn't very well say the CSI Officer he qualified was now unqualified, and he did not want to hurt the guy's credibility on the issues that helped him. Hence the defense hogtied the Assistant District Attorney. The defendant, whose defense was self defense leading to an accident which ultimately killed the victim, "proved" the viability of that defense using the other side's witness and thereby making their expert his "expert".

The lesson here for the offering party is that they must be very circumspect concerning the parameters of their expert's testimony. The offering party should be careful not to allow the opposing party an opportunity to box them into over-committing their expert. To a great extent this is the opposite of what an offering party may be expecting. They are likely more afraid of the witness being under-qualified by opposing counsel's vior dire. Hence at the very least, the offering party should be the one who states the parameters of the offered witness's expertise.

Mining for diamonds is not easy. One must know the rules of evidence and of qualifying an expert. The examiner must know as much about the subject matter as the expert does. Judicious use of the Internet, use of trade association magazines (often found online) and Search engine review of witnesses names, as well as old fashioned investigation techniques (such as getting out of the office and speaking to the witnesses) can help counsel gather enough information to understand the subject area of an expert on the limited issues in counsel's case.

One must also get out of the destructive cross mindset5. Destructive cross is like a battering ram, and is fun to perform, but this prism is more akin to investigation. By inviting the jury to investigate with you, and using the witnesses produced by your adversary, you add credibility to the cross-examination, and an element of fun in it too (the fun is in watching both the offering attorney and the witness squirm while they try to figure out what you are doing.) Further it establishes you as an expert too, and one the jury should look to in order to get the "skinny" on the facts during summations.

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