Updated Jan. 30, 2014 4:09 p.m. ET
BOSTON—Federal prosecutors will seek the death penalty against accused Boston Marathon bomber Dzhokhar Tsarnaev, U.S. Attorney General Eric Holder said Thursday.
Mr. Tsarnaev has pleaded not guilty to all charges against him, including using a weapon of mass destruction during the April 15 attack that left three dead and more than 260 wounded, including 16 people who lost legs.
“The nature of the conduct at issue and the resultant harm compel this decision,” Mr. Holder said in a statement.
In the federal system, the decision to seek to execute a suspect ultimately rests with the attorney general after the U.S. attorney handling the case makes a recommendation. Carmen Ortiz, the U.S. attorney for Massachusetts, made her recommendation last year, but it wasn’t made public. Ms. Ortiz said Thursday her office supports the decision and is prepared to move forward with the prosecution.
According to officials familiar with the decision, the factors that weighed in favor of death included photographic evidence allegedly showing Mr. Tsarnaev leaving one of the bombs next to 8-year-old Martin Richard, who later died, as well as a screed he allegedly wrote on the inside of a boat just before his capture, in which he took credit for the attack.
A government filing on Thursday alleged Mr. Tsarnaev betrayed the U.S. and “demonstrated a lack of remorse.”
Mr. Tsarnaev’s legal team includes Judy Clarke, a death-penalty expert with experience in high-profile cases where capital punishment was in play. She represented “Unabomber” Theodore Kaczynski, for example, and Jared Loughner, who killed six and wounded 13 in a Tucson, Ariz., shooting in 2011. Ms. Clarke couldn’t immediately be reached for comment.
Authorities believe Mr. Tsarnaev, 20 years old, and his older brother Tamerlan planted two bombs near the marathon finish line. Tamerlan died days later amid a firefight with police. The younger Mr. Tsarnaev, who was badly injured when he was captured, has been held under strict confinement rules at a federal prison hospital west of Boston.
State prosecutors have also charged Dzhokhar Tsarnaev in the killing of a Massachusetts Institute of Technology police officer. Days after the bombing, the brothers allegedly killed the officer while trying to take his gun in a bid to flee the area. According to investigators, the brothers had decided to leave Boston because the FBI seemed to be close to identifying them as suspects in the bombing.
Some of the injured survivors said they didn’t want to talk about Mr. Tsarnaev, and were focused instead on their ongoing recovery. Several are still going through surgeries.
Lillian Campbell, grandmother of Krystal Campbell, a 29-year-old restaurant manager from suburban Boston who was killed in the attack, said she received little comfort from Thursday’s announcement. “I don’t want to discuss it. I’m too upset,” she said. “It’s not going to help her any.”
The other people killed include Lu Lingzi, a Boston University graduate student and Chinese citizen; and Sean Collier, the 26-year-old MIT police officer.
Although Massachusetts doesn’t have a state-level death penalty—the last local execution was in 1947—federal authorities can still seek capital punishment there. In the most recent case, a jury sentenced confessed serial killer Gary Lee Sampson to death in 2003, although a judge found an issue with one of the jurors eight years later and overturned the decision. Ms. Ortiz continues to push for the death penalty in that case.
Since 1988, when the federal government reinstated a death penalty, only three people have been put to death under federal law, including Oklahoma City bomber Timothy McVeigh. But the attorney general has authorized requesting that penalty nearly 500 times over the past 25 years, according to recent data from the Federal Death Penalty Resource Counsel.
A jury has to unanimously agree to capital punishment during sentencing. In many federal cases, jurors wound up imposing life sentences instead, and the death penalty was taken off the table in many others due to plea bargains before trial.
The attorney general’s decision “by no means guarantees that [the Boston case] will go to trial with the death penalty still a possibility,” said Richard Dieter, executive director at the Death Penalty Information Center, a Washington-based nonprofit organization that opposes capital punishment.
But Walter Prince, a former federal prosecutor who is now a partner at Prince Lobel Tye LLP in Boston, doesn’t expect the federal government to backtrack on its death-penalty pursuit.
“If not this case, when?” he said. “I don’t think there’s going to be a change whatsoever.”
—Andrew Grossman and Jennifer Levitz contributed to this article.