Court Opinion

ID: 9602207
Source: CourtListenerOpinion
Date Created: 2023-08-22 01:52:28.758515+00
Date Added: 2024-06-11T18:02:01.484539
License: Public Domain

*533LENT, J.,
concurring.
I concur in the result, and I concur that the admissibility of the kind of evidence with which we are here concerned should be judged by the same rules as are used generally with respect to the admissibility of opinion evidence of witnesses who are expert in a given field. I concur with what I believe the majority is trying to express by the following statement:
“One of the rules is that an expert’s opinion must be based upon the facts in evidence or upon the facts within the personal knowledge of the expert.”
I do not concur with the statement as written.
An expert’s opinion amounts to the conclusion which he draws from certain facts that he assumes to exist for the predicate of his conclusion. Whether those facts actually exist is for the trier of fact to determine. That determination is dependent upon whether there is evidence from which those facts could be found to exist by the trier of fact.
If there is evidence in the record from which the trier of fact could find the existence of a certain fact, the expert may assume that fact to exist. If the existence of that fact is necessary to the validity of the opinion expressed by the expert, but the trier of fact fails to find that the fact exists, the trier of fact should disregard that opinion.
There is no such thing as a “fact” within the personal knowledge of the expert. There may be evidence within the personal knowledge of the expert, from which he infers the existence of a fact, but his inference may be found by the trier of fact to be erroneous just as in the case of the inferences to be drawn from the evidence within the personal knowledge of any other witness.
For example, a witness may testify that he saw an object lying on the ground a certain distance and direction away from a certain fire hydrant. That testimony is evidence from which the trier of fact may find that the object was in that location, i.e., that the fact exists that the object was in that location. On the other hand, for any number of reasons the trier of fact might find that the fact does not *534exist. For example, the trier of fact might find that other evidence is more believable as to the location of the object or that the witness who testified to the location was not credible.
Now, it may be that the witness who testifies to the location of the object in the above example is the very witness who is being asked for an expert opinion based upon the location of the object. If it be assumed that he is testifying truthfully, what it is that is in his personal knowledge is what he believes he perceived through his senses. That is not necessarily “fact”; it is only evidence from which the existence of “fact” can be established. The trier of fact may accept or reject that location as fact, just as in the case of any other witness.
In expressing an opinion, an expert may assume to be in existence any fact which could be found to exist by the trier of fact from evidence in the record. If there is no evidence, from the expert or any other source, from which the existence of a given fact could be found, the expert’s opinion may not be received, if a necessary predicate of that opinion is the existence of that very fact.
In the case at bar, there was no evidence in the record to establish a basis for the trier of fact to find that the location of the deceased’s body was that upon which the expert witness predicated his opinion; therefore, his opinion evidence could not be received over objection.