Casepin
Back to cases

Case file

Boston Marathon Bombing

SOLVED2013Boylston Street, Boston, Massachusetts3 SOURCESUPDATED JUL 2026
Illustrative

On April 15, 2013, during the 117th Boston Marathon, two homemade pressure cooker bombs detonated 14 seconds and 210 yards apart near the finish line on Boylston Street in Boston, Massachusetts. The explosions killed three civilians — Krystle Marie Campbell, 29; Lu Lingzi, 23; and 8-year-old Martin William Richard — and injured 264 others, including 16 people who lost limbs. Rescue and medical personnel already stationed for the marathon provided immediate aid, and authorities closed a large area around the blast site as investigators searched for explanations, initially suspecting no known threat had been flagged by intelligence agencies.

The FBI led the investigation, working with the ATF, CIA, National Counterterrorism Center, and DEA. Evidence recovered at the scene — including ball bearings, nails, and pressure cooker fragments — indicated the devices were homemade. On April 18, three days after the bombing, the FBI released images of two unidentified suspects, later identified as brothers Tamerlan and Dzhokhar Tsarnaev.

That evening, the brothers shot and killed MIT Police officer Sean Collier, 27, in his patrol car, then carjacked a vehicle in Allston-Brighton, taking the owner hostage before he escaped. Officers located the brothers in Watertown, where a shootout ensued in which an estimated 200-300 shots were fired and the brothers threw improvised explosives. Tamerlan Tsarnaev was shot and then run over by his brother as he fled in the stolen vehicle; Tamerlan died shortly afterward at a hospital. Boston Police officer Dennis Simmonds was injured by a grenade during the shootout and died from his injuries on April 10, 2014. MBTA officer Richard Donohue Jr. was critically wounded by crossfire but survived.

An extensive manhunt followed, with a 20-block area of Watertown searched door-to-door and residents of surrounding communities asked to shelter in place. On the evening of April 19, a Watertown resident discovered Dzhokhar Tsarnaev hiding in a boat in his backyard. Tsarnaev was shot and wounded by police before being taken into custody.

During questioning, Dzhokhar Tsarnaev acknowledged his role in the bombings, stating that he and his brother were motivated by U.S. military action in Iraq and Afghanistan, were self-radicalized, and had learned bomb-making from Inspire magazine, published by al-Qaeda in the Arabian Peninsula. He said the brothers had also intended to bomb Times Square in New York City.

Tsarnaev was charged in federal court with use of a weapon of mass destruction and other offenses. His trial began in March 2015, and on April 8, 2015, he was convicted on all 30 counts. He was sentenced to death on June 24, 2015. In July 2020, an appeals court vacated the death sentence over jury-selection issues, but on March 4, 2022, the U.S. Supreme Court reversed that ruling and reinstated the death sentence. Several associates of Dzhokhar Tsarnaev, including roommates and an acquaintance of Tamerlan, were separately charged and convicted of obstruction-related offenses for actions taken after the bombing.

Key facts

Victims
Dennis Simmonds, Sean Allen Collier, Martin William Richard, Krystle Marie Campbell, Lu Lingzi
Date
2013
Location
Boylston Street, Boston, Massachusetts
Case status
solved

Case timeline

  1. 2013-04-15

    Two pressure cooker bombs detonate near the Boston Marathon finish line, killing three people and injuring hundreds.

  2. 2013-04-18

    FBI releases images of two bombing suspects; that evening the Tsarnaev brothers shoot and kill MIT police officer Sean Collier and carjack a vehicle.

  3. 2013-04-19

    Watertown shootout occurs; Tamerlan Tsarnaev is killed. A manhunt follows, and Dzhokhar Tsarnaev is found hiding in a boat and taken into custody that evening.

  4. 2013-04-22

    Formal criminal charges are brought against Dzhokhar Tsarnaev in federal court.

  5. 2014-04-10

    Boston Police officer Dennis Simmonds dies from injuries sustained during the Watertown shootout a year earlier.

  6. 2015-04-08

    Dzhokhar Tsarnaev is found guilty on all 30 counts.

  7. 2015-06-24

    Dzhokhar Tsarnaev is sentenced to death.

  8. 2020-07-30

    The U.S. Court of Appeals for the First Circuit vacates Tsarnaev's death sentence, citing jury-selection issues.

  9. 2022-03-04

    The U.S. Supreme Court reverses the First Circuit and reinstates Tsarnaev's death sentence.

Best coverage

No approved coverage links are attached yet.

People

  • Robel Phillipos

    CONVICTED

    Convicted on two charges of lying to police about being in Tsarnaev's dorm room; sentenced to three years in prison.

  • Dennis Simmonds

    VICTIM

    Boston Police officer injured by a grenade during the Watertown shootout; died April 10, 2014 from his injuries.

  • Tamerlan Tsarnaev

    CONVICTED

    Co-perpetrator of the bombing; died during the Watertown shootout on April 19, 2013 before facing prosecution.

  • Sean Allen Collier

    VICTIM

    MIT police officer shot and killed by the Tsarnaev brothers on April 18, 2013.

  • Dias Kadyrbayev

    CONVICTED

    Pleaded guilty to obstruction of justice for helping dispose of Dzhokhar Tsarnaev's belongings; sentenced to six years in prison.

  • Khairullozhon Matanov

    CONVICTED

    Pleaded guilty to destroying records and making false statements in a federal terrorism investigation; sentenced to 30 months in prison.

  • Martin William Richard

    VICTIM

    Killed by the second bomb, age 8.

  • Krystle Marie Campbell

    VICTIM

    Killed by the first bomb at the marathon finish line, age 29.

  • Azamat Tazhayakov

    CONVICTED

    Convicted of obstruction of justice and conspiracy; sentenced to 42 months in prison.

  • Dzhokhar Tsarnaev

    CONVICTED

    Convicted on 30 federal charges including use of a weapon of mass destruction; sentenced to death, which was reinstated by the U.S. Supreme Court on March 4, 2022.

  • Lu Lingzi

    VICTIM

    Killed by the second bomb, age 23, Boston University graduate student.

Roles reflect public records and court outcomes at the time of writing — supporting citations are on file under Sources.

Places

Boylston Street, Boston, Massachusetts

42.3498, -71.0789

View on the map

Common questions

What happened to the victim?
On April 15, 2013, brothers Tamerlan and Dzhokhar Tsarnaev detonated two homemade pressure cooker bombs near the finish line of the Boston Marathon, killing three people and injuring hundreds. Days later they killed an MIT police officer and engaged in a shootout with police; Tamerlan died and Dzhokhar was captured. Dzhokhar Tsarnaev was later convicted on 30 federal charges and sentenced to death.
Where did the bombing happen?
Boylston Street, Boston, Massachusetts.
Who was convicted?
Robel Phillipos (Convicted on two charges of lying to police about being in Tsarnaev's dorm room; sentenced to three years in prison.), Tamerlan Tsarnaev (Co-perpetrator of the bombing; died during the Watertown shootout on April 19, 2013 before facing prosecution.), Dias Kadyrbayev (Pleaded guilty to obstruction of justice for helping dispose of Dzhokhar Tsarnaev's belongings; sentenced to six years in prison.), Khairullozhon Matanov (Pleaded guilty to destroying records and making false statements in a federal terrorism investigation; sentenced to 30 months in prison.), Azamat Tazhayakov (Convicted of obstruction of justice and conspiracy; sentenced to 42 months in prison.), and Dzhokhar Tsarnaev (Convicted on 30 federal charges including use of a weapon of mass destruction; sentenced to death, which was reinstated by the U.S. Supreme Court on March 4, 2022.).
What is the current status of the case?
Status: solved.
More cases in Massachusetts

Sources

  1. ENCYCLOPEDICBoston Marathon bombingWikipedia · 2026-07-10
  2. PRESSContemporaneous coverage — The New York TimesThe New York Times · 2026-07-10
  3. PRESSContemporaneous coverage — CBS NewsCBS News · 2026-07-10