Excluding "Rebuttal" Expert Testimony Under FRE 404(b) and FRE 703

Marijuana distribution conviction was vacated because of the erroneous admission of prosecution rebuttal psychiatric testimony (contesting defendant's contention that he suffered a “brain injury" that made him more vulnerable" to criminal "manipulation” by others); the prosecution expert's review of defendant's “rap sheet” as a basis of his rebuttal opinion that the defendant had “extensive prior contacts with law enforcement” before the accident should have been excluded as not based on sufficient facts or data in the expert's field under FRE 703, as well as "was far more prejudicial than it was probative," under FRE 403 and FRE 404(b), in United States v. Santini, 656 F.3d 1075 (9th Cir. Sept. 8, 2011) (No. 10-50391) (per curiam)

When is an expert's opinion not closely tied to his or her purported area of expertise, so that it should be excluded? Often the dispute regards an expert's qualifications, rather than exploration of the relationship between the purported expertise and the issue upon which an expert opinion is rendered. A recent case in the Ninth Circuit highlights this issue, in which the circuit found that it was prejudicial for the court to admit prosecution rebuttal expert psychiatric opinion regarding the defendant's criminal intent because of an alleged traumatic brain injury before the charged crime.

In the case, the defendant was apprehended crossing the U.S.-Mexico border with a large quantity of marijuana in his vehicle. He was charged with intending to distribute it. At trial, the defendant's theory was that "someone else had placed the marijuana in his car without his knowledge" and that he "may have been tricked." This was entirely possible contended the defense because the defendant had suffered a "traumatic brain injury" only three years before he was apprehended at the border with marijuana. Santini, 656 F.3d at 1077. The defendant sought, and the trial court admitted into evidence, expert testimony by "a clinical psychologist, [who] testified that Santini had suffered “a severe traumatic brain injury” and that tests showed the defendant had "permanent cognitive deficits” which negated his criminal intent.

Against this evidence, the prosecution presented its own expert who was a psychiatrist and who testified that he did not detect the defendant suffered from "any ... brain injury [that] made him more vulnerable to manipulation" by others. The expert based his assessment, in part, on the contention that the defendant's rap sheet had grown not appreciably changed after the supposed brain injury than before the injury. The defendant's criminal "rap sheet" showed that the defendant's criminal run-ins before the brain injury were as "extensive" as after the injury, suggesting that it made no difference in defendant's criminal intent. This was illustrated by the defendant's record of considerable "contacts with law enforcement" disclosed by his rap sheet. Santini, 656 F.3d at 1077.

The defendant was convicted and as part of his appeal, he contended that the prosecution's rebuttal evidence was not admissible and that the court error in admitting it was not harmless. To dispose of this question, the circuit applied a four-part test to determine admissibility of evidence under FRE 404(b) (see below). It found that two prongs of the test were deficient.

First, the test used in the Ninth Circuit required that the proponent of the other act evidence show that "there is sufficient evidence to support ... that the defendant committed the similar act" under FRE 404(b). The witness concluded with an opinion that the brain injury had no effect on the defendant's ability to form a criminal intent based on the “similar behavior” defendant displayed before the accident as after it. The defense objected to this testimony regarding the rap sheet and what inferences could be drawn from it.

To rebut this defense contention, the prosecutor presented its own expert who opined that the injury had no effect on the defendant's criminal action. The circuit found that this expert failed to present "sufficient evidence to support a finding by the jury that Santini had extensive law enforcement contacts." Indeed, the circuit explained:

...the only evidence presented by the government was [government expert witness] Dr. Kalish's testimony that he had reviewed Santini's “rap sheet.” Dr. Kalish admitted on cross-examination that he found the rap sheet hard to understand, and his report relaying the information contained in the rap sheet did not distinguish among arrests, convictions, or other “contacts” with law enforcement.
In addition, the rap sheet itself was not admitted into the record or a "examined by the district court. The defense also argued that this particular rap sheet was unreliable because it listed multiple allegations arising from the same incident as separate contacts. We conclude that the testimony of a psychiatrist relating disputed information contained in a rap sheet, which was neither admitted into the record nor examined by the district court, was not evidence that could support a finding by the jury that Santini had “extensive” law enforcement contacts. Dr. Kalish's testimony on this matter was, thus, not admissible under Rule 404(b). Santini, 656 F.3d at 1078.


Not only was the government showing of one requirement for admission of the other act evidence deficient, the the circuit outlined deficiencies with another required element:

Dr. Kalish's testimony also fails the fourth prong of our Rule 404(b) test. Dr. Kalish testified that Santini's criminal history was significant because it was “similar behavior” to the charged conduct. This is therefore a case that would trigger the fourth prong of the test and require that the prior “act is similar to the offense charged.” Romero, 282 F.3d at 688. Santini's prior convictions, however, were for simple possession; other contacts included arrests for indecent exposure and assault. This conduct is not similar to the importation of marijuana and thus lacks probative value.
Santini, 656 F.3d at 1078.


The problem with the government's showing was rooted in its failure to attend to the requirements set forth by FRE 702 and FRE 703 for the presentation of expert testimony, which would support its showing that prior act evidence was admissible with regard to the defendant's intent. As explained by the circuit:

[E]xpert testimony must satisfy the requirements of Rule 702, which provides that an expert's opinion must be “based upon sufficient facts or data.” Fed.R.Evid. 702. For the reasons outlined above, the rap sheet was not sufficient to form the basis of Dr. Kalish's opinion that Santini had engaged in “similar” criminal behavior prior to his brain injury. An expert in one field (Dr. Kalish was a psychiatrist) cannot express an opinion relying on data that requires expertise in another field (here, a rap sheet that would require interpretation by an expert in law enforcement record-keeping).
Santini, 656 F.3d at 1078 (citing United States v. Chang, 207 F.3d 1169, 1171–74 (9th Cir. 2000) (affirming the exclusion of an international finance expert's testimony because he lacked expertise in identifying counterfeit securities)).


Nor was the error in admitting the prior act evidence harmless. As explained by the circuit the prejudicial nature of the evidence had implications for admission of the evidence at trial. Its damage was done despite efforts by the trial judge to soften its impact so that the effort could be dismissed as harmless. As explained by the Circuit, "the statement that Santini had 'extensive' prior law enforcement contacts was far more prejudicial than it was probative in assisting the jury to evaluate Dr. Kalish's opinion. Although the district court instructed Dr. Kalish to use general language in an attempt to “sanitize” the criminal history, simply referring to Santini's prior contacts as “extensive” prevented the jury from evaluating whether those contacts were in fact similar to the charged conduct. At the same time, Dr. Kalish's testimony was highly prejudicial, inviting the jury to infer that prior to his 2005 accident Santini imported or distributed drugs." Santini, 656 F.3d at 1079.

As explained by the Ninth Circuit in Santini, the proffered expert rebuttal evidence was not admissible under the four-part test employed in the Ninth Circuit:

Rule 404(b) “permits evidence of prior wrongs or acts to show proof of motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident.” The Ninth Circuit uses a four-part test to determine the admissibility of evidence pursuant to Rule 404(b): 'Such evidence may be admitted if: (1) the evidence tends to prove a material point; (2) the other act is not too remote in time; (3) the evidence is sufficient to support a finding that defendant committed the other act; and (4) (in certain cases) the act is similar to the offense charged." The evidence regarding Santini's criminal history is inadmissible because it fails the third and fourth prongs of this test.
Santini, 656 F.3d at 1078 (citing United States v. Romero, 282 F.3d 683, 688 (9th Cir.2002).

Federal Rules of Evidence
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