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personpersonJohn SawickiJohn SawickiDigital-forensics and cell-tower expert retained by Sigfredo Garcia's defense.← All People
Expert witness

John Sawicki

Courtroom still of John Sawicki.

Digital-forensics and cell-tower expert retained by Sigfredo Garcia's defense.

AppearedGarcia–Magbanua
MentionedMagbanua Retrial
143 lines·6 proceedings·2 mentions·2 trials

About

Sawicki’s testimony helps explain the defense’s treatment of communications records, cloud-data gaps, and cell-tower evidence in the joint trial, while his later appearance reflects continued defense-expert involvement.

John Sawicki is a defense expert in computer forensics and cell-tower analysis. In the Garcia–Magbanua 2019 Joint Trial, he testified about comparisons between call-detail records and iCloud data, message counts, communications applications, and cell-tower connections. He explained that absent iCloud entries did not establish why material was missing or disclose its content or recipients, and he addressed limits on interpreting tower connections and message totals. During questioning, he also discussed deleted FaceTime activity, communications evidence involving Katherine Magbanua, and the limits of his information about Luis Rivera. In magbanua-retrial-2022, defense counsel identified him as an expert and obtained permission for him to observe Sergeant Christopher Corbitt’s testimony under a reciprocal arrangement.

Trial Record (6)

GMGarcia–MagbanuaSep 26, 2019 – Oct 11, 2019Called by defense

On Day 8, defense digital-forensics expert John Sawicki compared communications records and explained limits on inferences from missing cloud data and cell-tower connections.

Day 8

DirectJohn Sawicki - DirectJohn SawickiSaam Zangeneh2highlights98lines spoken

Summary

Defense expert John Sawicki described limits in iCloud, call-detail, and cell-tower records, including messages absent from Charlie Adelson's backup.

Highlights (2)

Quote“All I can say is it's not in the icloud backup when that was created. So it could have been deleted. It could have -- there could have been some other reason it didn't back up to the cloud, but all we know is it wasn't captured.”— John SawickiQualifies the defense expert's conclusion about messages absent from the backup.Open in transcript →Watch this moment ▶
CrossJohn Sawicki - CrossJohn SawickiChristopher DeCoste2highlights10lines spoken

Summary

Sawicki explained that phones do not necessarily use the nearest cell tower and may communicate from miles away.

Highlights (2)

testimony highlightSawicki explained that a phone may connect with different towers depending on signal strength, network conditions, and geography, rather than necessarily using the nearest tower.Open in transcript →Watch this moment ▶
Quote“The cell phone is going to connect to the tower with the strongest, cleanest signal. That could be the closest tower. It could not be the closest tower.”— John SawickiSummarizes the expert's qualification that the nearest tower is not necessarily the one a phone will use.Open in transcript →Watch this moment ▶
CrossJohn Sawicki - CrossJohn SawickiAnna Norris2highlights22lines spoken

Summary

Sawicki agreed his message total could include non-text notifications and that phone activity could be consistent with Jessica Rodriguez's house.

Highlights (2)

Quote“Frankly, that's the overall number, yes.”— John SawickiSawicki clarified that the 3,084 figure was an overall count rather than a content-verified message total.Open in transcript →Watch this moment ▶
RedirectJohn Sawicki - RedirectJohn SawickiSaam Zangeneh1highlight11lines spoken

Summary

Sawicki said he lacked all of Luis Rivera's contact information and agreed that deleted FaceTime activity or disposable phones can limit phone-record comparisons.

Highlights (1)

testimony highlightSawicki testified that he had not determined how many phones belonged to Luis Rivera and did not have all of Rivera's contact information, qualifying the scope of the comparison with Charlie Adelson's records.Open in transcript →Watch this moment ▶