Opinion
A jury found the defendant, Cyrus Griffin, guilty of manslaughter in the first degree with a firearm in violation of General Statutes § 53a-55a (a)
1
and carrying a pistol without a permit in violation of General
*268
Statutes § 29-35.
2
The trial court rendered judgment
3
in accordance with the jury verdict, from which the defendant appealed to the Appellate Court, claiming, inter alia, that the trial court improperly had excluded certain expert testimony during the hearing on the defendant’s motion to suppress his oral confession to the police following his arrest.
4
The Appellate Court rejected the defendant’s claim;
State
v.
Griffin,
The opinion of the Appellate Court sets forth the following facts that the jury reasonably could have found. “At or around 2 p.m. on January 29,1998, Denard Lester, accompanied by the defendant, robbed the eighteen year old victim, Tyshan Allbrooks, in New Haven. Lester took from the victim what witnesses described as a necklace or a medallion made of gold. The victim immediately went to a friend’s nearby house, reported the incident to the police and, during an interview, provided a statement to the police who had responded to her complaint. After the robbery, the defendant, Les *269 ter and Tobias Greene were passengers in an automobile being operated by Paul Little. The defendant and Lester were fourteen years of age; Greene and Little were sixteen years of age.
“A short time later, at or around 2:45 p.m., the victim was walking along Whalley Avenue in New Haven when she was seen by the defendant, who was in the automobile with his acquaintances and was aware that the victim had reported the robbery to the police. The defendant remarked that ‘snitches get stitches,’ got out of the automobile and chased the victim on foot. The victim ran [into] a convenience store where she asked an attendant to call for assistance. The defendant caught up to the victim, and shot her twice in the chest and four times in the back with his pistol, thereby causing her death.”
State
v.
Griffin,
supra,
The Appellate Court opinion also sets forth the following additional relevant facts and procedural history. “Prior to trial, on April 5, 1999, the defendant filed a motion to suppress ‘potential testimony and other evidence of any statements made by the [defendant.’ It is not contradicted that, on February 2, 1998, police detectives arrested the defendant in an apartment in New Haven after they [had] discovered him hiding in a closet. The police thereafter took the defendant to the New Haven police department where Detectives Leroy Dease and Gilbert Burton interviewed him. At trial, Dease testified that the defendant told him that Lester had taken the victim’s necklace from her and that after the robbery, the defendant, Lester, Greene and Little drove around New Haven. Dease further testified that the defendant told him that Greene, upon observing the victim walking across an intersection, [had] ordered [the defendant] to get out of the car and shoot the victim. Dease then testified that the defendant confessed that he [had] followed the victim [into] the *270 convenience store and, with Greene standing nearby, ‘pulled out his small pistol and shot [the victim] several times.’ According to Dease, the defendant also told him that he was afraid that Greene was going to shoot him and believed that Greene had ordered him to shoot the victim because [the defendant] owed Greene $300. Burton testified that he was present during the defendant’s arrest and interview, and testified as to the circumstances under which the defendant [had] made his confession.
“The defendant supported his motion to suppress by asserting [inter alia] that he had made the statements, in which he confessed to having shot the victim . . . involuntarily in violation of his due process rights . . . .” Id., 427-28.
“On April 19, 2001, prior to the hearing on the defendant’s motion to suppress, the state filed a motion in limine to exclude ‘any and all opinion testimony of any expert witness regarding the waiver of Miranda 5 rights predicated upon an evaluative protocol created by Thomas Grisso or related to such protocol.’ The state argued that such evidence was based on ‘scientific, technical and/or specialized knowledge which is unreliable.’
“At the evidentiary hearing on the defendant’s motion to suppress . . . the defendant elicited testimony from Madelon V. Baranoski, a clinical psychologist employed by the Connecticut Mental Health Center at Yale University [School of Medicine]. Baranoski ... is an associate clinical professor at Yale [University School of Medicine] and the associate director of the [New Haven] court clinic, which is affiliated with the law and psychiatry division of [the] department of psychiatry [of the school of medicine]. Baranoski testified that as part of her professional duties, she evaluates approximately *271 200 separate defendants in an average year to [determine] whether they are competent to stand trial.
“Baranoski testified that evaluating an individual’s competency in regard to a particular stage of trial proceedings involves identifying what tasks are involved at such stage of the proceedings . . . and determining whether the individual possesses the competency to understand the issues and tasks related thereto. [Baranoski] testified that she evaluated the defendant to determine whether he possessed the competency to understand his Miranda rights. Baranoski explained that her evaluation involved several methods: A clinical interview, [intelligence quotient (IQ)] testing, personality testing, testing for reading and spelling proficiency, testing for arithmetic ability and general achievement testing. In addition to testing the defendant to determine his ‘overall competency,’ Baranoski also tested the defendant with a ‘set of questions that had to do with the specific tasks in understanding the Miranda warning [s] and making a choice to waive [his] rights.’
“Baranoski explained that those questions were part of a protocol developed by . . . Grisso, a forensic psychologist who has devoted his professional efforts to issues regarding ‘juvenile competency’ and who works with a research group that researches issues of competency. She also testified that the Grisso testing ‘instrument,’ which is part of the study protocol, consists of four parts that are scored by the test administrator.” Id., 429-30. “The first part tests a person’s ability to explain accurately, in his or her own words, what aspects of the Miranda warnings mean. The second part tests ‘recognition’ oí Miranda rights, and the third part tests comprehension of the vocabulary [used in] the warnings. Finally, the fourth part, which involves pictures and stories about fictional persons being interrogated, tests a person’s ability to recognize, during an *272 interrogation, the function of the Miranda warnings.” Id., 430 n.4.
“Baranoski explained the defendant’s results as to each [part] of the Grisso test; she reported that he scored in the bottom 20 percent of juvenile test takers. She opined, on the basis of the defendant’s results on the Grisso test, as well as on the basis of the defendant’s results on the other evaluative measures she [had] employed dining her evaluation, that the defendant ‘did not understand the right to remain silent as it applied to incriminating information . . . and [that] he also did not understand the role of an attorney during the interrogation process.’
“The state argued in its . . . motion in limine that expert testimony based on the Grisso protocol was inadmissible under the standard for admissibility of expert testimony set out in
Daubert
v.
Merrell Dow Pharmaceuticals, Inc.,
“In his opposition to the state’s motion in limine, [defense counsel] argued that it was ‘unclear’ whether the court should apply a
Daubert
type of analysis to testimony related to or based on the Grisso test. [Defense counsel] then addressed the Grisso test’s admissibility in terms of the criteria for admissibility
*273
set forth in
Daubert.
[Defense] counsel argued that the Grisso test was admissible under what he [deemed to be]
Porter’s
‘liberal standard of admissibility.’ ”
State
v.
Griffin,
supra,
The trial court granted in part and denied in part the defendant’s motion to suppress. “The court suppressed any statements that the defendant had made to the police after such time when the police attempted to tape-record their interview, when, as the court found, the defendant had expressed his desire to terminate the [interview]. The court permitted testimony concerning the defendant’s oral confession prior to that point.” Id., 428.
The trial court thereafter issued a separate memorandum of decision in which it explained that it had granted the state’s motion in limine. “The court deemed inadmissible Baranoski’s testimony insofar as it concerned the Grisso test and her expert opinion insofar as it was based, in whole or in part, on the results of the defendant’s performance on such test. The court based its ruling on its conclusion that the evidence relating] to the Grisso [protocol] was inadmissible under [Porter]. The court concluded that the defendant had failed to prove that ‘the methodology underlying the technique is scientifically valid.’ ” 6 Id., 431.
At trial, the state adduced testimony in its case-in-chief regarding that portion of the defendant’s oral confession that the trial court had determined was admissible. At the conclusion of the trial, the jury found the
*274
defendant guilty of manslaughter in the first degree with a firearm and carrying a pistol without a permit. On appeal, the Appellate Court rejected the defendant’s claim that the trial court had abused its discretion in excluding Baranoski’s testimony regarding the Grisso test. Id., 442. In particular, the Appellate Court concluded that the trial court reasonably had determined, first, that that testimony was subject to the test adopted by this court in
Porter,
id., 439; and second, that the testimony did not satisfy
Porter’s
standard for the admissibility of scientific evidence. See id., 440-42. We thereafter granted the defendant’s petition for certification to appeal, limited to the following issue: “Whether the Appellate Court properly determined: (a) that a . . .
Porter . . .
hearing was required; and (b) that its application properly resulted in the exclusion of . . . Baranoski’s testimony . . . .” (Citation omitted.)
State
v.
Griffin,
supra,
Before addressing the merits of the defendant’s claims, we set forth the principles that govern our review of the trial court’s ruling. “It is axiomatic that [t]he trial court’s ruling on the admissibility of evidence is entitled to great deference. In this regard, the trial court is vested with wide discretion in determining the admissibility of evidence. . . . Accordingly, [t]he trial court’s ruling on evidentiary matters will be overturned only upon a showing of a clear abuse of the court’s discretion.” (Citations omitted; internal quotation marks omitted.)
State
v.
Perkins,
I
We first consider whether the trial court abused its discretion in subjecting Baranoski’s testimony regarding the Grisso test to review under Porter. The defendant contends that Porter is inapplicable because the Grisso test does not constitute “scientific evidence” within the contemplation of Porter. We disagree with the defendant’s contention.
“In
[Porter],
we adopted the test for determining the admissibility of scientific evidence set forth in
Daubert
v.
Merrell Dow Pharmaceuticals, Inc.,
[supra,
In adopting the
Daubert
approach in
Porter,
we “held that scientific evidence should be subjected to a flexible test, with differing factors that are applied on a case-by-case basis, to determine the reliability of the scientific evidence. . . .
Porter
explicitly stated that the flexible
Daubert
approach was a better approach than the test of general acceptance in the scientific community, which was established in
Frye
v.
United States,
“Although this court in
Porter
explicitly adopted the
Daubert
test to determine the admissibility of scientific evidence; see
State
v.
Porter,
supra,
*277
State
v.
Reid,
supra,
Similarly, in
State
v.
Hasan,
supra,
In contrast to the expert testimony in the aforementioned cases, Baranoski’s testimony concerning the Grisso protocol was not the kind of evidence that readily may be understood and evaluated by a fact finder on the basis of common sense or independent powers of observation or comparison. As the Appellate Court aptly explained: “Baranoski testified that the Grisso test is an evaluative tool: It consists of a series of four subtests that are meant to measure juvenile competency relative to Miranda warnings. She testified that psychologists have tested the Grisso test and concluded that there is ‘a consistency in the way it measures what it measures.’ She testified that the questions in the Grisso test are standardized. Portions of the test *279 include pictures and hypothetical stories, both of which involve situations in which Miranda rights are implicated and about which test questions are asked.
“Baranoski also testified that a test taker’s responses to each inquiry are scored. She testified that ‘the scores give you an idea of how other people have rated answers consistent with what Grisso had found in his initial development of this tool. So, you look at how those responses compare with other responses that reflected a strong understanding or a not so good understanding of that particular question. There is an overall score for the test, and the scores are just a way to think about the extent to which a part of this test was understood or not. So, if somebody gets them all right, looking at that, I say, well, compared to other people understanding the section, the person I am evaluating understood it [as] well as anybody else understood that section.’
“Baranoski further testified that she scored the defendant’s responses to each section of the test and that she compared the scores to a summary of scores compiled by Grisso for his ‘target group’ of test takers. Baranoski testified that this scoring information is set forth in tables provided with the testing materials. Although Baranoski testified that the defendant scored in the bottom 20 percent of juvenile test takers, she testified that the test [cannot] answer the question of whether he understood his
Miranda
rights. Baranoski testified in that regard that she considered the defendant’s results on many different tests and that she applied her expertise in evaluating the defendant in reaching her expert opinion that he ‘did not understand his right to remain silent as it applied to incriminating information, and [that] he also did not understand the role of an attorney during the interrogation process.’ ”
State
v.
Griffin,
supra,
The Appellate Court explained further: “The testing materials [utilized by Baranoski], including questions *280 about words and phrases and questions based on hypothetical stories and pictures, constitute a scientific tool designed to assess comprehension of Miranda rights. It is difficult to label those instruments as constituting something otherwise. The scoring materials provided with the testing instruments contained] detailed instructions as to how each response should be graded. The object of the Grisso test is to assign point values to a test taker’s responses and to compare that test taker’s scores to the scores of test takers in Grisso’s original study group. The test is based on the premise that the questions, hypothetical stories and pictures effectively will measure comprehension and that the scoring reflects accurately such comprehension.” Id., 438-39.
Thus, Baranoski’s testimony concerning the Grisso protocol was predicated on the results of a scientific instrument or tool and not solely on her observations, educational background or experience. “[T]he . . . testimony [at issue] was based on a method employed by the expert witness to assess comprehension. Neither powers of observation, comparison nor common sense, however, could be used [by the trier of fact] to assess the validity of the method underlying the Grisso test and in determining whether it accurately measures what it purports to measure. Instead, the methodology underlying the test rested on . . . scientific principles, theory or experiment in the field of psychology.” Id., 439. We agree with the Appellate Court that, in such circumstances, a Porter inquiry was a necessary predicate to admissibility.
The defendant contends that we should apply a more lenient standard in determining whether a
Porter
analysis is necessary when, as in the present case, scientific evidence is proffered to a court rather than a jury. We reject this argument. It is true that one reason for requiring a threshold determination of reliability in
*281
regard to such evidence is to preclude the use of testimony based on “obscure scientific theories . . . that [have] the potential to mislead lay jurors awed by an aura of mystic infallibility surrounding scientific techniques, experts and the fancy devices employed.” (Citation omitted; internal quotation marks omitted.)
State
v.
Reid,
supra,
In further support of his claim that he should have been permitted to adduce Baranoski’s testimony regarding the Grisso test without a
Porter
hearing, the defendant relies on two cases from other jurisdictions in which testimony relating to that test was admitted into evidence, apparently without being subject to scrutiny under
Daubert, Frye
or similar standards for the admissibility of scientific evidence. See
State
v.
Caldwell,
We therefore conclude that the trial court properly determined that Baranoski’s testimony based in whole or in part on the Grisso protocol was subject to a Porter inquiry. We turn next to the issue of whether the trial court reasonably concluded that Baranoski’s testimony failed to meet the Porter standard.
II
Generally, “[a] witness qualified as an expert by knowledge, skill, experience, training, education or otherwise may testify in the form of an opinion or otherwise concerning scientific . . . knowledge, if the testimony
*283
will assist the trier of fact in understanding the evidence or in determining a fact in issue.” Conn. Code Evid. § 7-2. In order to determine whether an expert witness’ testimony concerning scientific evidence will assist the trier of fact, the trial judge must undertake “a two part inquiry [in accordance with Porter]: [1] whether the reasoning or methodology underlying the [scientific theory or technique in question] is scientifically valid and ... [2] whether that reasoning or methodology properly can be applied to the facts in issue. ... In other words, before it may be admitted, the trial judge must find that the proffered scientific evidence is both reliable and relevant.” (Internal quotation marks omitted.)
State
v. Kelly,
With regard to the reliability prong of the inquiry, the court in
Porter
identified four nonexclusive factors for “judges to consider in determining whether a particular theory or technique is based on scientific knowledge: (1) whether it can be, and has been, tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) the known or potential rate of error, including the existence and maintenance of standards controlling the technique’s operation; and (4) whether the technique is, in fact, generally accepted in the relevant scientific community.”
State
v.
Porter,
supra,
In its memorandum of decision concerning the state’s motion in limine, the trial court concluded that the defendant had failed to establish “that the Grisso test has sufficient scientific validity ... for the court to accept it as rehable evidence.” The trial court further found that the methodology underlying the Grisso test had not been subject either to sufficient testing since its development in 1981 or to adequate peer review and publication. In addition, the trial court concluded that the defendant had failed to demonstrate that the Grisso test is generally accepted in the relevant scientific community.
In support of his claim that the trial court abused its discretion in excluding Baranoski’s testimony concerning the Grisso test, the defendant contends that the court engaged in an unduly mechanistic, and therefore improper, review of the factors that we identified in Porter as among those that are relevant to a determination of the admissibility of scientific evidence. In particular, the defendant contends that the trial court failed to give proper weight to certain factors that tend to support the admissibility of Baranoski’s testimony regarding the Grisso test, including Baranoski’s expert *285 ence and qualifications and the scientific and legal literature.
We are unpersuaded by the defendant’s claim. Although Baranoski testified that the Grisso protocol has been discussed in various professional journals and at a number of seminars, the trial court reasonably found, upon due consideration of Baranoski’s testimony, that the Grisso protocol had not been critically evaluated by Grisso’s peers and that it had not been generally accepted as scientifically valid. Similarly, Baranoski’s testimony did not establish that the Grisso test is widely used; in fact, Baranoski acknowledged that she had administered the Grisso test to a juvenile on but one prior occasion. Moreover, contrary to the defendant’s assertion, there is nothing in the record to suggest that the court, in evaluating the validity of the Grisso test, failed to give appropriate weight to Baranoski’s professional standing and credentials. On the contrary, the record reflects that the trial court properly considered the relevant Porter factors and reasonably found them to be lacking. Thus, there is no indication that the court’s balancing of the pertinent Porter factors was unreasonable or otherwise flawed.
In challenging the trial court’s conclusion, the defendant emphasizes Baranoski’s testimony regarding the purported validity of the Grisso test based on “inter-rater reliability” and “test, retest reliability.” According to Baranoski, interrater reliability is a measure of the reliability of a test based on the extent to which the results of the test are the same when the test is administered to the same subject by different testers. Test, retest reliability is a measure of the reliability of a test based on the extent to which the results of the test are the same when it is given to the same subject on two different occasions by the same tester. These measures of reliability, however, focus upon the relative consistency of the results of the test rather than upon the *286 validity of the methodology upon which the test is founded. Consequently, to the extent that the defendant maintains that Baranoski’s testimony regarding the purported reliability of the Grisso test necessarily was entitled to significant weight, that assertion is not persuasive.
The defendant also underscores the fact that the empirical studies from which the Grisso protocol was developed have been cited in a number of judicial opinions and professional journal articles. The great majority of those references, however, do not concern the methodology underlying the Grisso protocol but, rather, stand for the general proposition, gleaned from those studies, that juvenile arrestees often have particular difficulty understanding Miranda warnings. Thus, the references to the Grisso test identified by the defendant provide little, if any, support for his contention that the trial court had abused its discretion in excluding Baranoski’s testimony.
We note, finally, that, in agreeing with the Appellate Court that the trial court did not abuse its discretion in excluding Baranoski’s testimony concerning the Grisso test, we do not denigrate the credentials or expertise of either Baranoski or Grisso. On the contrary, we have no reason to doubt that both are well respected in their fields. Although that fact was one of several factors relevant to the determination of whether Baranoski’s testimony was sufficiently rehable to warrant its consideration by the trial court; see
State
v.
Porter,
supra,
The judgment of the Appellate Court is affirmed.
In this opinion the other justices concurred.
Notes
The state charged the defendant with murder in violation of General Statutes § 53a-54a (a). The jury, however, found the defendant guilty of the lesser included offense of manslaughter in the first degree with a firearm.
The state also charged the defendant with one count of robbery in the second degree in violation of General Statutes § 53a-135 (a) (1) and one count of larceny in the second degree in violation of General Statutes § 53a-123 (a) (3). The jury found the defendant not guilty on those counts.
The trial court sentenced the defendant to a total effective term of forty years imprisonment, execution suspended after thirty years, and five years probation.
On appeal to the Appellate Court, the defendant also challenged the admissibility of certain testimony adduced by the state regarding the circumstances surrounding his oral confession, and the oral confession itself, on the ground that the trial court improperly concluded that the defendant knowingly, intelligently and voluntarily had waived his rights under
Miranda
v. Arizona,
Miranda
v.
Arizona,
In its memorandum of decision on the state’s motion in limine, the trial court also explained, however, that, in rendering its decision on the defendant’s motion to suppress, the court had considered other testimony by Baranoski regarding the defendant’s ability to understand his Miranda rights. That testimony included the defendant’s lower than average intelligence quotient, his sixth grade reading level, his repeated absence from school, his difficulty in forming concepts, his attention and concentration deficits and his long-standing use of drugs and alcohol.
As we previously have noted, this court had applied the
Frye
test of general acceptance in cases decided before
Porter.
See
State
v.
Porter,
supra,
Likewise, in
State
v.
Borrelli,
supra,
Although Grisso himself testified as an expert witness in Daoud, it was unclear from the opinion of the Michigan Supreme Court whether his testimony was based in whole or in part on his protocol. Even if we assume that it was, no objection apparently was raised to such testimony.
