Person Jessica Hyde Trial 1Trial 2Jessica Hyde is a digital forensics expert from Magnet Forensics who testified for the prosecution in both trials about the timing of the "how long to die in cold" Google search on Jennifer McCabe’s phone. ← All People
🔬 Expert Witness · Magnet Forensics

Jessica Hyde

Trial 1Trial 2
634 lines 7 proceedings 2 trials
Courtroom still of Jessica Hyde.

About

Jessica Hyde is a digital forensics expert employed by Magnet Forensics, the company behind the AXIOM forensic analysis tool. She was retained by the prosecution to analyze Jennifer McCabe's iPhone and offer expert opinions on the timing and deletion status of the disputed Google search for 'how long to die in cold.' Her testimony spans six proceedings across both trials, consistently arguing that the 2:27 a.m. timestamp reflects browser tab movement rather than the time of the search itself, and that her analysis places the search at 6:24 a.m. She also examined John O'Keefe's phone for health and activity data relevant to the timeline of his death.

Key Points

  • Hyde's central opinion — offered in both trials — was that the 2:27 a.m. timestamp on McCabe's phone comes from the BrowserState.db artifact, which records when a browser tab moved, not when a search was performed, and that corroborating artifacts in MobileSafari's plist and the KnowledgeC database place the actual search at 6:24 a.m.
  • In Trial 1, Hyde identified two specific errors in defense expert Richard Green's affidavit: that he misinterpreted the BrowserState.db timestamp as the time of the search, and that he incorrectly concluded the search had been deleted based on its presence in the write-ahead log — a common professional misreading she said she teaches against.
  • During Trial 1 cross-examination, Yannetti secured the concession that Hyde's analysis could not affirmatively rule out a search occurring at or before 2:27 a.m., and established that the scope of her examination — limited to Safari search history — was dictated by Detective Tully, not chosen independently.
  • In Trial 2, Alessi used Ian Whiffin's 12:32:09 a.m. lock-button artifact to challenge Hyde's report wording about no post-12:20 a.m. device interaction. Hyde agreed a lock-button press can be an interaction but said she had not reviewed or validated Whiffin's specific artifact; she distinguished direct user interaction from device motion, while allowing that the step-data wording could be interpreted to extend another 20 seconds.
  • On Trial 2 recross, Alessi established that Cellebrite had removed the 2:27 a.m. timestamp from its automated parsing in a May 2024 update but offered no substantive public explanation for doing so, while AXIOM — Hyde's own company's tool — continued to recover and display the artifact, leaving the evidentiary weight of the timestamp unresolved.

Trial Record (7)

Trial 1 First Criminal Trial Apr 29, 2024 – Jul 1, 2024 2 proceedings

Day 25

Direct Jessica Hyde Adam Lally 4 highlights 108 lines spoken
Summary

Jessica Hyde testified about Safari search artifacts, stating that a 2:27 browser-state timestamp did not establish the search time and that she found no evidence of deletion.

Highlights (4)
Quote

“My conclusion is that there was a search at 0247 a.m. for Hockomock Sports, that that browser was in use, and there were continual searches due through the night.”

Hyde stated her timeline conclusion before distinguishing the later search entries.

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Quote

“In regards to those artifacts pertaining to those search terms, I had no evidence of deletion.”

Hyde gave her direct conclusion on whether the search-term artifacts showed deletion.

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Key Moment

Hyde explained that the browser-state timestamp reflects tab activity rather than necessarily the time a search was made, while describing the two searches she identified at 6:23 and 6:24 a.m.

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Cross Jessica Hyde David Yannetti 4 highlights 25 lines spoken
Summary

Hyde said the 2:27 a.m. timestamp did not indicate search time and that her review was limited to Safari search history.

Highlights (4)
Quote

“That timestamp is not indicative of a time of search. So the question is difficult to answer, because I can't say that that timestamp tells me anything about the time of search.”

Hyde distinguished the tab timestamp from evidence of when a search occurred.

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Key Moment

Hyde maintained that the 2:27 a.m. timestamp was associated with a tab, not a Google-search time, and said the extraction gave no indication of a search at or before that time.

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

Day 11

Direct Jessica Hyde Hank Brennan 6 highlights 121 lines spoken
Summary

Jessica Hyde testified that a Safari tab timestamp did not mark when the "hos long to die in cold" search was made, placing it at about 6:24 a.m.; she also opined that neither the search nor older call-log entries were user-deleted.

Highlights (6)
Quote

“What I can state to a scientific degree of certainty is that that search occurred at 6:24 a.m., and was the last search in the tab that had been opened at 2:27.”

Hyde gave her central opinion on the disputed search timing.

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Quote

“My opinion is there was no deletion that occurred by the user because it is not something a user can delete.”

Hyde stated her opinion that the Safari item was not user-deleted.

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Quote

“The opinion is that I can see that it's done by the device itself utilizing the unified logs, that the system is deleting the 201st every time a new call is received or outgoing.”

Hyde attributed removal of older call-log entries to the device's system behavior rather than user action.

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Show 2 more
Cross Jessica Hyde Robert Alessi 3 highlights 292 lines spoken
Summary

Defense challenged Ms. Hyde's reports on phone activity, the 2:27:40 timestamp, and evidence handling; she acknowledged limits in artifacts she had not reviewed and agreed that the phone was not isolated according to the preservation practice she described.

Highlights (3)
Quote

“I cannot contest it because I do not recall looking at that specific artifact.”

Ms. Hyde said she had not reviewed the artifact defense used to question the timing in her report.

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Quote

“Cellebrite did remove that time stamp from the tool, that is correct.”

Ms. Hyde acknowledged a change in Cellebrite's automated reporting of the disputed timestamp.

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Quote

“Correct. It is not in accordance with the best practices. I agree. I would have Faradayed it.”

Ms. Hyde agreed that the phone handling reflected in the data did not follow the preservation practice she described.

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Redirect Jessica Hyde Hank Brennan 2 highlights 52 lines spoken
Summary

Hyde defended the independence and methodology of her phone analysis, explained limits on timestamp and health-step data, and said her report could not establish all overnight phone movement.

Highlights (2)
Recross Jessica Hyde Robert Alessi 4 highlights 36 lines spoken
Summary

Hyde answered further questions about timestamp tools, phone isolation, and call-log data, saying Mr. O'Keefe's phone appeared not to have been in a Faraday bag from 6:00 a.m. to noon.

Highlights (4)
Quote

“I analyzed her phone to see if there had been deletions of call logs and what I found was that there were records that were removed by the system and not recoverable from that database but were recoverable from biomes.”

Hyde distinguished system-removed call-log records from recoverable data found in another source.

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Key Moment

Hyde testified that the phone identified as Mr. O'Keefe's appeared to have received signal from 6:00 a.m. to noon and not to have been placed in a Faraday bag, subject to her stated qualification about a potentially failing bag.

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