Brian J. Corcoran, Jr. Testimony & Transcripts - Dzhokhar Tsarnaev Case Archive

About

Brian J. Corcoran, Jr. testified for the prosecution as an FBI special agent bomb technician about evidence recovered on Laurel Street in Watertown. On Day 35, he described arriving around 3:00–3:30 a.m. on April 19, a secondary safety search that found no additional live devices, resident evacuation, and evidence collection in three geographic zones. He explained how items were marked, photographed, collected, and transferred for forensic examination, and authenticated photographs admitted without objection.

His testimony distinguished suspicious electronics from a complete explosive device. A computer bag underwent an additional X-ray examination after modified electronics drew attention; Corcoran said it lacked the other components needed for an explosive device. When the defense questioned his personal knowledge, he clarified that he witnessed the contents being removed and personally removed the transmitter, while information about the bags' origins came from other technicians.

On Day 36, Corcoran identified pressure-cooker remains, pipe components, BB-bearing material, electronics, and other recovered items. He said the Watertown pressure cooker matched the brand and type of the Boylston Street remains, although he believed its size differed. He described shrapnel on residential properties and as much as a block away, but clarified that he had not witnessed the explosion. The court permitted descriptions of the transmitter's physical features while limiting explanations that entered expert testimony, including discussion of a dead man switch.

Under Watkins's cross-examination, Corcoran clarified vehicle locations in scene exhibits and confirmed that the laptop and documents associated with Tamerlan Tsarnaev came from the same computer bag, found a few feet from the Honda Civic. The government had withdrawn its laptop offer during direct examination. When the defense offered it on cross-examination, the court admitted Exhibit 1544 as a physical object but expressly excluded its electronic data.

Trial Record (8)

2015 Trial2015 Federal TrialJan 5, 2015 – Jun 24, 2015Called by prosecution

Brian J. Corcoran, Jr. testified as an FBI bomb technician about Watertown bomb debris, recovered electronics, and evidence collection. His testimony connected a laptop with documents associated with Tamerlan Tsarnaev; the court admitted the physical laptop but excluded its electronic data.

Day 34

Mar 17, 2015

ProceduralDefense Exhibits on Cross-Examination: Foundation RequirementsMentioned

Summary

The Court declined a blanket objection to defense exhibits on cross-examination. Counsel also disputed witness notice, exhibit identification, and preparation time.

Mentioned in this proceeding.

Day 35

Mar 18, 2015

DirectBrian J. Corcoran, Jr. — DirectBrian J. Corcoran, Jr.William D. Weinreb2highlightsMentioned110lines spoken

Summary

Corcoran described Watertown evidence recovery, clarified his firsthand handling of bag contents, and authenticated photographs admitted without objection.

Mentioned in this proceeding.

Highlights (2)

testimony highlightCorcoran said an X-ray examination found no IED in the computer bag, although modified electronics were present.Open in transcript →

objectionAfter Watkins questioned personal knowledge, Corcoran said he witnessed removal of the bag's contents and personally removed the transmitter. Testimony continued.Open in transcript →

Day 36

Mar 19, 2015

DirectBrian J. Corcoran, Jr. — Direct (continued)Brian J. Corcoran, Jr.William D. Weinreb192lines spoken

Summary

Corcoran identified Watertown bomb debris and other recovered evidence; the court limited technical testimony and left the laptop's admissibility unresolved.

sidebarLimits on Radio-Controlled Transmitter TestimonyDuring Brian J. Corcoran, Jr. — Direct (continued)

Summary

Defense counsel challenged transmitter testimony as undisclosed expert testimony, while the government said the witness was only identifying physical components from his bomb-technician experience.

sidebarComputer Admissibility and TimingDuring Brian J. Corcoran, Jr. — Direct (continued)

Summary

Counsel disputed admitting the physical computer separately from its contents, with the government reserving relevance and 403 objections.

sidebarDead Man Switch Testimony and Expert NoticeDuring Brian J. Corcoran, Jr. — Direct (continued)

Summary

Counsel debated the relevance of Laurel Street items, proposed testimony limited to their consistency with dead man switch components, and an objection that expert testimony had not been noticed.

CrossBrian J. Corcoran, Jr. — Cross-ExaminationBrian J. Corcoran, Jr.Timothy G. Watkins29lines spoken

Summary

Corcoran clarified scene exhibits and the laptop's recovery with Tamerlan Tsarnaev's documents. The court admitted the physical laptop but excluded its electronic data.

sidebarAdmission of Computer Hardware and DataDuring Brian J. Corcoran, Jr. — Cross-Examination

Summary

The government objected on relevance and 403 grounds to admitting the computer’s contents before the relevance of particular items was established.