United States v. McCluskey
United States District Court for the District of New Mexico
954 F. Supp. 2d 1224 (2013)
Laboratories that conduct DNA testing may specify a level of DNA in a sample below which testing of the sample could produce unreliable results. This level of DNA is known as the stochastic threshold, and a quantity of DNA that falls below the threshold is classified as a low copy number (LCN). John Charles McCluskey, Tracy Province, and other individuals (defendants) were charged with murdering a couple near a highway rest stop in New Mexico. The United States (plaintiff) gathered swab samples of DNA from the victims’ car and a handgun allegedly used in the crime. One swab taken from the handgun’s magazine contained only 215 picograms of DNA, which was below the 250-picogram stochastic threshold set by the New Mexico Department of Public Safety (NMDPS). The government’s DNA analyst at the NMDPS laboratory, Carrie Zais Davis, conducted LCN testing on the sample from the magazine. Davis asserted that the testing showed to “a reasonable degree of scientific certainty” that Province was the sole source of DNA on the sample. Province and the other defendants moved to exclude Davis’s testimony, challenging the reliability of LCN DNA testing. At an evidentiary hearing, the district court asked Davis to justify her conclusion that the test results from the sample were reliable even though the amount of DNA was below the stochastic threshold. Davis responded simply that she believed based on her experience that the results were reliable, but she did not cite any scientific studies or other support for her assertion. Although the government cited some scientific support for the reliability of LCN testing results, the government’s authorities all involved different testing procedures from those used by the NMDPS laboratory.
Rule of Law
Holding and Reasoning (Herrera, J.)
What to do next…
Unlock this case brief with a free (no-commitment) trial membership of Quimbee.
You’ll be in good company: Quimbee is one of the most widely used and trusted sites for law students, serving more than 724,000 law students since 2011. Some law schools—such as Yale, Berkeley, and Northwestern—even subscribe directly to Quimbee for all their law students.Unlock this case briefRead our student testimonials
Learn more about Quimbee’s unique (and proven) approach to achieving great grades at law school.
Quimbee is a company hell-bent on one thing: helping you get an “A” in every course you take in law school, so you can graduate at the top of your class and get a high-paying law job. We’re not just a study aid for law students; we’re the study aid for law students.Learn about our approachRead more about Quimbee
Here's why 724,000 law students have relied on our case briefs:
- Written by law professors and practitioners, not other law students. 45,600 briefs, keyed to 983 casebooks. Top-notch customer support.
- The right amount of information, includes the facts, issues, rule of law, holding and reasoning, and any concurrences and dissents.
- Access in your classes, works on your mobile and tablet. Massive library of related video lessons and high quality multiple-choice questions.
- Easy to use, uniform format for every case brief. Written in plain English, not in legalese. Our briefs summarize and simplify; they don’t just repeat the court’s language.