Reliability and Admissibility of Fingerprint Evidence

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsInferenceLaw

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Passage

Passage A In this appeal of his criminal conviction, the defendant challenges the fingerprint evidence used against him at trial, claiming that fingerprint identification theory has not been adequately tested. He cites the inability of the fingerprint examiner who incriminated establishing that no two persons have identical fingerprints.

The defendant claims that there are no established error rates revealing how often fingerprint examiners incorrectly identify a fingerprint as a particular person’s, and asserts that fingerprint examiners lack uniform, objective standards. He cites testimony given by the fingerprint examiner at trial that there of “points of identification” required for a positive identification.

Although fingerprint identification has not attained the status of scientific law, it has been used in criminal trials for 100 years, and experts have long concurred about its reliability. While further testing and the development of even more consistent standards may be desirable, this court sees no that has so ably withstood the test of time.

While it may be true that different agencies require different degrees of correlation before permitting a positive identification, fingerprint examiners are held to a consistent “points and characteristics” approach to identification. As the fingerprint expert testified at the defendant’s trial, examiners are regularly subjected to testing and proficiency requirements, and uniform standards discretion in crediting testimony that fingerprint identification has an exceedingly low error rate.

Passage B Fingerprint examiners lack objective standards for evaluating whether two prints “match.” There is simply no consensus about what constitutes a sufficient basis for identification. Some examiners use a “point-counting” method that entails counting the number of similar “ridge” characteristics on prints, but there is no fixed requirement about how many is no generally agreed-on standard for determining precisely when to declare a match.

Although we know that different individuals can share certain ridge characteristics, the chance of two individuals sharing any given number of identifying characteristics is unknown. How likely is it that two people could have four points of resemblance, or five, or eight? Moreover, fingerprints used in forensic identification are typically partial and such questions decisively, yet the answers are critical to evaluating the value of fingerprint evidence.

The error rate for fingerprint identification in actual practice has received little systematic study. How often do fingerprint examiners mistakenly declare a match? Although some proficiency tests show examiners making few or no errors, these tests have been criticized a 34 percent rate of erroneous identification.

What this question is testing

Inference

Your task

Find what must be true based on what the passage or stimulus states.

Common trap

Answers that are plausible or likely but not actually guaranteed by the text.

Winning move

Keep only the choice the statements fully support — eliminate anything that requires an extra assumption.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question

10.

It can be inferred that the author of passage

Answer choices

Correct74% picked this
a judge presiding over an appeal of a
Why this is right
We can tell from the final sentence of the 3rd paragraph that this passage was written by a judge ("this court sees no reason to reject a form of evidence that has so ably withstood the test of time"). That's actually a good enough reason to pick this answer, since it's the only answer that says that the author is a judge. But the final sentence of the passage suggests that we're at the Appellate (i.e. appeals) level, because this judge is reviewing the trial (lower) court's decision and vindicating it: The trial court below was therefore within its discretion in crediting testimony that ... [blah blah blah]
Skill tested: Inference · how this choice captures the passage's function is the move to repeat next time.
74%
Attorney vs. Judge3% picked this
a defense attorney arguing an appeal of a client's
We're looking for judge, not attorney. An attorney can speak about "this court", but not for "this court". An attorney could say, "This court found in Marbury v. Madison that a plaintiff's right to [blah blah blah]". But only a judge can speak as the court, like we see at the end of the 3rd paragraph, "This court sees no reason to reject the fingerprinting evidence".
3%
Attorney vs. Judge13% picked this
a prosecutor arguing for the affirmation of a
We're looking for judge, not prosecutor. A prosecutor can speak about "this court", but not for "this court". A prosecutor could say, "And thus we ask this court to find the defendant guilty." But only a judge can speak as the court, like we see at the end of the 3rd paragraph, "This court sees no reason to reject the fingerprinting evidence".
13%
Professor vs. Judge8% picked this
a professor of law lecturing to a criminal
We're looking for judge, not professor. A professor can speak about "this court", but not for "this court". A professor could say, "This court found in Simpson v. Springfield that a plaintiff's right to [blah blah blah]". But only a judge can speak as the court, like we see at the end of the 3rd paragraph, "This court sees no reason to reject the fingerprinting evidence".
8%
Academic vs. Judge2% picked this
an academic presenting a paper to a group of
We're looking for judge, not academic. An academic can speak about "this court", but not for "this court". An academic could say, "This court found in Simpson v. Springfield that a plaintiff's right to [blah blah blah]". But only a judge can speak as the court, like we see at the end of the 3rd paragraph, "This court sees no reason to reject the fingerprinting evidence".
2%

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