Person Maureen Hartnett Trial 1Trial 2Massachusetts State Police forensic scientist who examined a Lexus SUV and John O’Keefe’s clothing. ← All People
🗣️ Witness

Maureen Hartnett

Courtroom still of Maureen Hartnett.

Massachusetts State Police forensic scientist who examined a Lexus SUV and John O’Keefe’s clothing.

Trial 1Trial 2
1,289 lines 9 proceedings 2 trials

About

Maureen Hartnett, a forensic scientist in the Massachusetts State Police Crime Laboratory’s criminalistics unit, examined Karen Read’s Lexus and John O’Keefe’s clothing. She documented damage to the SUV’s rear passenger side, collected apparent glass from its bumper and a hair from its rear quarter panel, and swabbed exposed portions of the taillight housing. She described the hair as consistent with human hair with a root. Blood screening of specified vehicle areas was negative; stains on the clothing screened and confirmed positive for blood. She also collected clothing debris for trace examination. On cross-examination, Hartnett said she had not determined whether the vehicle damage resulted from a pedestrian strike or when it occurred. She reported no visible stains or tissue on the SUV. Swabs she took from one of six cups containing red-brown stains were not tested for blood or DNA. She corrected the recorded date of her vehicle examination and said she had no information showing where certain items had been before the laboratory received them. At the retrial, she testified that a sweatshirt and T-shirt had been packaged together and their scrapings combined, so she could not assign particular debris to either garment. Defense counsel later argued that a prosecutor’s questioning of another expert misleadingly suggested holes in the back of the sweatshirt came from the incident. Laboratory records documented cuts Hartnett made during inspection and sampling. The prosecutor acknowledged a mistake, and the judge instructed jurors that the holes were made by the criminalist during a May 18, 2023 inspection.

Trial Record (9)

Trial 1 First Criminal Trial Apr 29, 2024 – Jul 1, 2024 4 proceedings

Day 19

Direct Maureen Hartnett - Direct Examination Maureen Hartnett Adam Lally 3 highlights 379 lines spoken
Summary

Hartnett described her forensic work on the Lexus SUV and clothing items, including a human-hair determination, reported blood-testing results, and a prior proficiency-test remediation.

Highlights (3)
Quote

“In this particular instance, I had an inconsistent answer with the expected laboratory result.”

Hartnett directly acknowledged the proficiency-test error that led to remediation.

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Quote

“With that alternate light source, I tested several stains on the sneakers, one of which screened positive for blood.”

Summarizes her reported screening result for the sneakers.

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Cross Maureen Hartnett Cross-Examination Maureen Hartnett Alan Jackson 4 highlights 217 lines spoken
Summary

Hartnett corrected the date of her sally-port examination and described limits on vehicle swabs, pooled collections, untested Solo-cup swabs, and pre-laboratory evidence-history information.

Highlights (4)
Quote

“The testing that I did on scene from the various areas of the undercarriage which I had mentioned before, the tire flaps, the edge of the bumper and the exhaust pipe, screened negative for blood.”

She described the reported result of her on-scene vehicle swabs.

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Quote

“I personally do not have any data that would indicate where those items of evidence were prior to them being accepted into the lab.”

She limited her knowledge of the evidence history before laboratory intake.

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Key Moment

Hartnett testified that one collection swab covered multiple external areas of the taillight housing, so the testing could not identify the particular swabbed location from which any DNA originated.

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Redirect Maureen Hartnett - Redirect Maureen Hartnett Adam Lally 1 highlights 8 lines spoken
Summary

Hartnett clarified that taillight-housing swabs came from exposed exterior areas and did not recall snow or ice on the vehicle.

Highlights (1)
Quote

“I took them from what would have been the exposed area of the taillight should the taillight have been intact. So I did not collect from any of the interior portions of the taillight that would have been protected by the exterior plastic piece.”

Hartnett specified the exterior, exposed location from which she collected the taillight-housing swabs.

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Trial 2 Retrial Apr 22, 2025 – Jun 18, 2025 5 proceedings

Day 15

Direct Maureen Hartnett - Direct Maureen Hartnett Hank Brennan 5 highlights 320 lines spoken
Summary

Forensic scientist Maureen Hartnett testifies about her examination of Karen Read's black Lexus SUV at the Canton Police Department and her subsequent lab analysis of John O'Keefe's clothing.

Highlights (5)
Quote

“I noticed there was some damage to the rear passenger area of the vehicle.”

Initial observation establishing the focus area of vehicle damage relevant to the case theory.

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Quote

“This item was quantity limited. The swab itself was quantity limited, meaning that they'd have to use up the whole swab in order to run DNA analysis.”

Explains that the quantity-limited swab was cut up for further testing and that the whole swab would be required to run DNA analysis.

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Quote

“That scraping was combined with the scrapings from the sweatshirt.”

Debris from the orange T-shirt and sweatshirt were combined into a single submission (item 7-18), a packaging decision relevant to trace evidence analysis.

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Quote

“It had missing pieces, but nothing was loose on the tail light housing itself at the time that I collected it.”

Establishes the condition of the tail light at collection, relevant to chain of custody questions about loose pieces found later in the evidence bag.

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Cross Maureen Hartnett - Cross Maureen Hartnett Robert Alessi 5 highlights 243 lines spoken
Summary

Defense attorney Alessi challenges forensic scientist Hartnett's vehicle examination, establishing that no damage, glass, or hair evidence was scientifically linked to a pedestrian strike and questioning evidence handling of solo cup blood samples.

Highlights (5)
Quote

“That would be outside the scope of my expertise. I don't make any conclusions on injuries on the person.”

Witness cannot connect arm wounds to anything on the vehicle, limiting the prosecution's ability to link vehicle damage to victim injuries through this witness.

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Quote

“Correct. At this time, those were not tested for blood at all. So I couldn't confirm that they were blood, and no additional testing was done.”

The solo-cup stains were not confirmed as blood, and the swabs received no additional testing. Hartnett returned the cups to a Canton police officer and did not know their subsequent custodian.

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Quote

“It was not difficult.”

Hartnett said the apparent glass was not difficult to remove with tweezers. Alessi's later travel-and-weather feasibility question was sustained for lack of proper foundation.

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Quote

“No, it in fact wasn't secured in any way on that quarter panel.”

Hair evidence was completely unsecured on a smooth vertical surface, undermining its evidentiary weight.

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Day 16

Cross Maureen Hartnett - Cross (Continued) Maureen Hartnett Robert Alessi 4 highlights 68 lines spoken
Summary

Robert Alessi continues cross-examination of forensic scientist Maureen Hartnett, focusing on the absence of biological testing on tail light fragments and on the co-mingling of clothing evidence and Hartnett's limited knowledge of its handling before laboratory receipt.

Highlights (4)
Quote

“Yes, the items were packaged together, so they were already co-mingled, so there was no way for me to determine which debris came from which item, and it would be misleading to label them as such, so I combined them.”

Establishes that the two clothing items were already co-mingled before lab analysis, making it impossible to attribute debris to a specific garment.

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Quote

“No, I don't know the source of the debris.”

Hartnett cannot identify whether debris on the clothing originated from the scene, an ambulance, a hospital, or elsewhere.

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Quote

“I have no knowledge of where they were stored or anything like that before that.”

Confirms Hartnett has no chain of custody information for evidence items submitted by the Norfolk Detective Unit prior to lab receipt.

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Redirect Maureen Hartnett - Redirect Maureen Hartnett Hank Brennan 5 highlights 47 lines spoken
Summary

Hank Brennan redirects forensic scientist Maureen Hartnett on the scope of her vehicle examination, the vehicle's condition when she saw it, evidence preservation, and hypotheticals about evidence placement, some of which were sustained.

Highlights (5)
Quote

“No, I was not.”

Confirms Hartnett was not at the scene the morning O'Keefe was found, establishing she has no firsthand knowledge of evidence collection conditions.

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Quote

“I did not note any. I also did not examine the interior of the vehicle.”

Hartnett testified that she did not note additional dents, scratches, or hair in response to the question asked, while also stating that she did not examine the vehicle interior. This does not establish that such evidence was absent everywhere on the vehicle.

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Quote

“No. To the best of my recollection, there was no snow on the vehicle when I saw it.”

Hartnett recalled that there was no snow on the vehicle when she saw it. The answer describes her examination-time recollection and does not establish the vehicle's condition at the incident.

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Quote

“I think there are really just too many variables to say either way.”

Hartnett said that too many variables prevented her from saying either way when an observed item was placed from a later examination. This was the admitted timing limitation; it did not establish that evidence had been placed on the vehicle.

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Show 1 more
Quote

“I would be looking for any item of evidence. I'm not specifically looking for anything. I'm just looking for anything that could potentially be evidence.”

Describes Hartnett's general search for potential evidence. It does not establish that her methodology could distinguish collision evidence from evidence placed later; the supplied placement-specific question was not answered.

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Recross Maureen Hartnett - Recross Maureen Hartnett Robert Alessi 2 highlights 6 lines spoken
Summary

Robert Alessi briefly recrosses Maureen Hartnett on one point about the gray hoodie's right sleeve damage, establishing she performed no analysis of what caused the hole.

Highlights (2)
Quote

“I wanted to correct something from the record yesterday. I wasn't sure when it was appropriate to do that.”

Hartnett requests to correct something from the prior day's record; the available transcript does not disclose the proposed correction or its disposition.

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