US Attorney General Eric Holder Thursday authorized federal prosecutors to seek the death penalty in the trial of Dzhokhar Tsarnaev, who is accused of killing three and wounding hundreds in a bombing near the finish line of the Boston Marathon last April.

“After consideration of the relevant facts, the applicable regulations and the submissions made by the defendant’s counsel, I have determined that the United States will seek the death penalty in this matter,” Mr. Holder said in a statement. “The nature of the conduct at issue and the resultant harm compel this decision.”

The government could have opted for a lesser prosecutorial hurdle of life in prison without parole, which would have avoided many uncertainties – including the possibility that even if convicted and executed, Mr. Tsarnaev might still attain martyr status, his death fueling further terrorism.

Instead, the government filed with the US District Court of Massachusetts in Boston the required notice of intent to seek the death penalty. In a statement, US Attorney for Massachusetts Carmen Ortiz said that her federal prosecutors in Boston “support this decision and the trial team is prepared to move forward with the prosecution.”

Indeed, some say prosecutors are likely sitting on a mountain of damning physical and other evidence against Tsarnaev, who faces 30 counts in the bombing, including use of a weapon of mass destruction resulting in death and the bombing of a public place. He is accused of exploding two homemade pressure cooker bombs with his brother, Tamerlan, at the finish line of the Boston Marathon on April 15, 2013, killing three, and injuring more than 260 people.

Dzhokhar Tsarnaev is also charged with later killing Massachusetts Institute of Technology police officer Sean Collier when the brothers tried to steal the officer’s gun. Tamerlan was killed in a gun fight with police later the same evening.

Still, the decision to seek the death penalty can be problematic for the government.

Over the past 4-1/2 years, the Justice Department has sought executions in several cases, but such cases can be protracted and none has yet seen any of those convicted placed on death row. During the past 50 years, the federal government has executed just three people, including Timothy McVeigh, convicted of the 1995 Oklahoma City bombing.

The cases of Ted Kaczynski, the convicted “Unabomber” who killed three and injured 23 others, and Eric Rudolph, the convicted “Olympic Park bomber” who killed two people and injured 111 others, both resulted in life sentences. As did the case of Jared Lee Loughner, who shot and killed six, injuring 11 including former US Rep. Gabrielle Giffords. In all those cases, as well as that of Zacarias Moussaoui, one of the 9/11 conspirators who survived, plea agreements resulted in life sentences that avoided the death penalty.

“History tells us that even in these federal murder cases with very egregious factors, and in which notoriety was high, the end result was not a death sentence,” says Richard Dieter, executive director of the Death Penalty Information Center, a nonprofit group that researches factors surrounding the application of the death penalty, but does not oppose it.

From 1993 to 2012, the Justice Department brought 88 capital punishment cases in states that didn't have a death penalty, the Huffington Post reported. Yet just seven defendants wound up on death row, according to data compiled by the Federal Death Penalty Resource Counsel Project.

Even so, the mere act of seeking the death penalty does lend prosecutors some distinct advantages, Mr. Dieter and other experts say.

The jury, for instance, is not simply a random group of people from Boston. Rather, it will be somewhat more conservative than it might otherwise be, because in order to be on the jury individuals must be found by the judge to be willing to apply the death penalty. That excludes those with more liberal views who oppose the death penalty on moral grounds.

Because the jury is going to be at least a bit more conservative than simply a random group, studies have shown that they are more likely to accept the word of police and prosecutors, perhaps making the prosecution’s effort a bit easier, Dieter says. Similar factors could come in the sentencing phase if Tsarnaev were to be found guilty, he says.

In Tsarnaev’s corner, however, are defenders that include anti-death penalty expert, Judy Clarke, who has turned back the death penalty in other high-profile cases. Ms. Clarke could work a similar life-in-prison plea deal – or even possibly ask the court for a change of venue, arguing that a trial in Boston could never be fair.

But she may not do that because it’s entirely possible that if the trial were moved, it could be assigned to a state with a far more conservative set of jurors, Dieter notes. Although Massachusetts does not itself allow the death penalty, a judge could order that any federal death sentence be carried out in a state like Indiana which does permit it. That would only follow, however, after years of appeals are exhausted.

“You know, this one might result in a death sentence, but it doesn’t necessarily have to be so,” Dieter says. “You just don’t know what will happen. We’ve all heard a lot about this guy from videos and whatnot, but there’s more about his life and influences before he even came to this country that will come out in a trial setting – and that can change things.”