Nicholas Bradford Testimony & Transcripts

About

Nicholas Bradford is a DNA analyst employed by BODE Technology, an accredited forensic laboratory. He was called by the prosecution in both trials to present the results of DNA testing performed on a tail light extract and a hair sample recovered from Karen Read's Lexus. His testimony centered on STR (short tandem repeat) mixture analysis establishing that John O'Keefe could not be excluded as a contributor to the tail light DNA mixture, while two Massachusetts State Police troopers — Bukhenik and Proctor — were statistically supported for exclusion.

Across Trials

In Trial 1, the defense waived cross-examination of Bradford entirely, leaving his statistical conclusions unchallenged. In Trial 2, Alan Jackson conducted a substantive cross focused on two points: pressing Bradford on the distinction between statistical exclusion and absolute exclusion for Proctor, and establishing that numerous individuals from the Albert household had never been compared to the tail light DNA sample. The cross did not undermine the O'Keefe inclusion statistic but framed the exclusion of other potential contributors as incomplete.

Challenges & Responses

In Trial 2, Alan Jackson cross-examined Bradford on the statistical asymmetry between Proctor's exclusion ratio (76,000 to one) and O'Keefe's inclusion ratio (740 nonillion), eliciting Bradford's acknowledgment that 'strong support for exclusion' is not the same as definitive exclusion. Jackson also highlighted that a number of individuals present the night of O'Keefe's death were never submitted for comparison to the tail light sample. Bradford maintained the accuracy and methodology of his reported findings throughout.

Key Points

Bradford testified that the DNA profile obtained from the tail light was at least 740 nonillion times more likely if John O'Keefe and two unknown unrelated individuals were contributors than if three unknown unrelated individuals contributed; he explained that a nonillion is a number with 30 zeros.
Bradford testified that the tail light DNA result was 46 million times more likely under a mixture of three unknown unrelated individuals than under a mixture of Trooper Yuri Bukhenik and two unknown unrelated individuals, which he described as very strong support for exclusion.
Regarding the hair sample recovered from the vehicle, Bradford testified that the DNA quantity was below the limit of detection for autosomal STR testing, explaining why a different analyst performed mitochondrial DNA analysis on the hair — a distinction Bradford walked through carefully for the jury.
On cross-examination in Trial 2, Bradford acknowledged that Trooper Michael Proctor's exclusion from the tail light mixture carried a likelihood ratio of 76,000 to one — statistically significant but orders of magnitude weaker than the nonillion-scale support for O'Keefe's inclusion — and that several other individuals had never been compared to the sample at all.

Trial Record (3)

Trial 1 First Criminal Trial Apr 29, 2024 – Jul 1, 2024 1 proceeding

Day 24 June 13, 2024

Direct Nicholas Bradford Adam Lally 3 highlights 89 lines spoken

Summary

Bradford testified that a taillight extract was a three-person DNA mixture, with very strong support for inclusion of John O'Keefe and support for exclusion of Yuriy Bukhenik and Michael Proctor; the hair sample did not yield a usable STR profile.

Highlights (3)

Quote

“Yes. So in this case when comparing the John O'Keefe profile, assuming a mixture of three individuals, it is at least 749 nonillion times more likely to be observed if it originated from John O'Keefe and two unknown, unrelated individuals than if from three unknown, unrelated individuals.”

Bradford stated the likelihood-ratio result supporting inclusion of John O'Keefe in the taillight mixture under the stated assumptions.

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Quote

“So in that case, assuming a mixture of three individuals, the DNA profile obtained is at least 46 million times more likely to be observed if it originated from three unknown, unrelated individuals than if from Yuriy Bukhenik and two unknown, unrelated individuals.”

Bradford gave the numerical basis for his stated exclusion conclusion concerning Yuriy Bukhenik.

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Key Moment

Bradford described the DNA-processing workflow, Bode's training, proficiency testing, and evidence chain-of-custody procedures.

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Trial 2 Retrial Apr 22, 2025 – Jun 18, 2025 2 proceedings

Day 18 May 19, 2025

Direct Nicholas Bradford Adam Lally 4 highlights 100 lines spoken

Summary

DNA analyst Nicholas Bradford testifies about DNA testing performed on evidence from Karen Read's vehicle tail light and a hair sample.

Highlights (4)

Quote

“John O'Keefe could not be excluded as a potential contributor to that mixture profile.”

Reports Bradford's conclusion that O'Keefe could not be excluded as a potential contributor to the tail light mixture.

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Quote

“it would be 740 nonillion times more likely that it was a mixture of John O'Keefe and two unrelated individuals versus three unknown unrelated individuals.”

Reports the likelihood ratio for O'Keefe and two unknown unrelated individuals versus three unknown unrelated individuals.

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Quote

“So he could not be visually excluded based on just comparing the profile to the STRmix output. So we do the likelihood ratio... So in this case it was 46 million times more likely that it was three unknown unrelated individuals versus Yuri Bukhenik and two unknown unrelated individuals. So that would be very strong support for exclusion.”

Reports Bradford's testimony that Bukhenik was not visually excluded on the initial comparison, followed by a likelihood ratio providing very strong support for exclusion.

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Quote

“the quantification results were below the limit of detection. So we would not expect to get an STR profile from that hair.”

Explains why the hair evidence required different (mitochondrial) DNA testing by another analyst.

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Cross Nicholas Bradford Alan Jackson 1 highlights 14 lines spoken

Summary

Alan Jackson cross-examines DNA analyst Nicholas Bradford about the statistical comparison involving Michael Proctor and asks whether Bradford was asked to compare four other named individuals' known DNA samples to the taillight sample.

Highlights (1)

Quote

“So, like I said, in this case, it's 76,000 times more likely that we would observe that evidence profile if it were three unknown unrelated individuals as opposed to Michael Proctor and then two unknown unrelated individuals.”

Bradford framed the 76,000 statistic as a comparison between two explanations of the evidence profile, rather than a population analogy.

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