Three people were killed at the marathon
Krystle Campbell, Lingzi Lu and eight-year-old Martin Richard were killed near the finish line of the Boston Marathon. Hundreds of other people were injured. The bombing triggered an intensive federal, state and local investigation and a multi-day manhunt.
MIT Police Officer Sean Collier was later killed during the brothers' flight from law enforcement. That homicide became part of the broader federal prosecution, but this page keeps the marathon victims distinct from the later events of the manhunt.
The investigation identified two brothers
Investigators used surveillance video, physical evidence, public tips and other evidence to identify Tamerlan and Dzhokhar Tsarnaev. Tamerlan died after a confrontation with police in Watertown. Dzhokhar was captured and charged federally.
The FBI later described the case as one of the largest and most complex investigations in its history. The prosecution introduced extensive forensic, digital, eyewitness and victim evidence at trial.
Federal conviction on all counts
A federal jury found Dzhokhar Tsarnaev guilty on all 30 counts in 2015, including capital counts connected to the deaths caused by the bombing. He did not contest that he participated in the bombing; much of the trial dispute centered on punishment and the relative influence of his older brother.
The jury recommended death on six capital counts, and the district court imposed the death sentence in June 2015.
The Supreme Court reinstated the death sentence
In 2020, the First Circuit Court of Appeals left most convictions intact but vacated the death sentence and ordered a new penalty proceeding. The United States appealed.
On March 4, 2022, the U.S. Supreme Court reversed that ruling and reinstated the death sentence. The Supreme Court's decision concerned jury selection and excluded mitigation evidence; it did not reopen Tsarnaev's guilt.
Collateral penalty litigation remains active
Later litigation raised different claims about whether jurors had been truthful or unbiased during jury selection. In March 2024, the First Circuit directed the trial judge to investigate specified juror-bias claims that could affect the death sentence.
In July 2025, the First Circuit rejected Tsarnaev's effort to remove the original trial judge from supervising that inquiry. Reporting at that stage emphasized that Tsarnaev's guilt was not at issue; the unresolved question concerns whether the penalty-phase result should stand.
Timeline
April 15, 2013: three people are killed and hundreds injured near the Boston Marathon finish line.
April 18–19, 2013: the manhunt culminates in Tamerlan Tsarnaev's death and Dzhokhar Tsarnaev's capture.
April 2015: a federal jury finds Dzhokhar guilty on all 30 counts.
June 2015: the district court imposes a federal death sentence.
July 2020: the First Circuit vacates the death sentence while leaving the core convictions intact.
March 4, 2022: the U.S. Supreme Court reinstates the death sentence.
March 2024: the First Circuit orders further inquiry into juror-bias claims affecting punishment.
July 31, 2025: the First Circuit rejects a request to recuse the trial judge from that collateral proceeding.