The Boston Marathon Bombing — 2013 Terror Attack

The Case

The Boston Marathon bombing is an American domestic terrorism case from 2013, in which two pressure-cooker bombs concealed in backpacks were detonated near the finish line of the Boston Marathon, killing three people and injuring hundreds. The attack was carried out by brothers Tamerlan and Dzhokhar Tsarnaev, and the case is solved: Dzhokhar Tsarnaev was convicted in federal court and sentenced to death, while Tamerlan was killed during the manhunt that followed.

The Crime

On the afternoon of April 15, 2013, at 2:49 p.m., two improvised explosive devices detonated within seconds of each other on Boylston Street in Boston, Massachusetts. One bomb exploded at the marathon finish line; the second went off a short distance away outside the Forum restaurant. Both devices were pressure cookers packed with explosives and shrapnel, hidden in backpacks placed at ground level among spectators.

The blasts tore through a dense crowd of runners, families, and onlookers gathered to watch one of the world's most famous road races. Three people were killed and hundreds more were injured, many of them severely, with numerous amputations among the wounded. The placement of the devices in a tightly packed public space was designed to maximize casualties.

The Victims

The bombing killed three people at the scene and injured hundreds of others. The supplied source materials do not list the names or ages of the deceased victims, so individual biographical details are not verified here. The injuries ranged from minor wounds caused by debris to life-altering traumatic injuries, including limb loss. Additional casualties occurred during the manhunt that followed, as documented in law enforcement retrospectives of the attack.

Investigation

The investigation was led by the FBI in cooperation with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), Boston Police, and other local and federal agencies. ATF's explosives expertise played a central role in identifying the materials and construction methods used to build the pressure-cooker bombs.

A defining feature of the inquiry was the sheer volume of evidence available. Investigators sifted through a massive quantity of surveillance footage, news photography, and bystander video and images to identify the two suspects walking through the crowd with backpacks. Within days, the FBI publicly released images of the suspects, who were soon identified as the Tsarnaev brothers — Tamerlan, the older brother, and Dzhokhar, born July 22, 1993, of Chechen and Avar descent.

The identification triggered a violent series of events. The brothers were linked to the killing of an MIT police officer and a carjacking, and a confrontation with police in Watertown left Tamerlan Tsarnaev mortally wounded. According to a Department of Justice Office of the Inspector General report, Dzhokhar was apprehended the following day, found hiding in a boat stored in a Watertown backyard on the evening of April 19, 2013. The same report notes that the FBI had received foreign intelligence about Tamerlan in 2011 and had closed an assessment after finding no nexus to terrorism at that time.

Trial and Verdict

Dzhokhar Tsarnaev was charged in federal court with a series of offenses including use of weapons of mass destruction resulting in death. In April 2015, a federal jury found him guilty, and he was subsequently sentenced to death for his role in the attack. Because Tamerlan Tsarnaev died from injuries sustained during the Watertown confrontation, he never stood trial.

The key evidence presented in the prosecution included surveillance and bystander video footage placing the brothers at the scene, photographic evidence of the backpacks, and forensic analysis of the explosive devices and their material signatures.

Today

The Boston Marathon bombing remains one of the most heavily documented terrorism cases in modern U.S. history. The case is officially solved: one perpetrator is dead and the other is under a federal death sentence, with subsequent appellate litigation continuing in the years after the original verdict. The attack reshaped public-event security in the United States and prompted reviews of how intelligence on potential extremists is shared between agencies. A wide range of news features and retrospectives continue to revisit the bombing, the manhunt, and the survivors' long recoveries.