Prosecutors often balk at capital cases

“There are a lot of people in the office who are opposed to the death penalty and would not be interested in working on such a case, including a lot of capable and experienced people in the office,” said Mark Pearlstein, a capital punishment opponent who was first assistant US attorney in Boston from 1996 to 2000.

He opted out of overseeing a 1998 case in which the office sought the death penalty against Kristen Gilbert, a Veterans Affairs nurse charged with — and ultimately convicted of — fatally poisoning some of her patients.

Pearlstein, now in private practice at McDermott, Will & Emery, said he told his colleagues simply, “I’m against the death penalty. I can’t do it.”

He and others say the office’s divisions over the death penalty should not be surprising: Federal prosecutors are drawn from the communities in which they live.

Massachusetts has a robust anti-death-penalty tradition and banned capital punishment for state crimes more than 30 years ago. It’s been nearly 60 years since the death penalty has been carried out in Massachusetts.

But for federal prosecutors, the death penalty is not an abstract concept but an actual punishment they must speak about in a courtroom and persuade 12 jurors unanimously to impose.

The four prosecutors assigned to the Tsarnaev case — William Weinreb, Aloke Chakravarty, Nadine Pellegrini and Steven Mellin — have worked as a team in the guilt phase of the trial, and it remains unclear how they will handle the expected death penalty phase.

Some former prosecutors said they — and they believe many others — would eagerly accept the chance to prosecute Tsarnaev, based on the horrendous nature of his crimes and a chance to seek justice for the hundreds of victims.

Though Tsarnaev pleaded not guilty, his defense attorney admitted in opening statements March 4 that Tsarnaev and his older brother, Tamerlan, killed three and injured 260 others at the race and — a few days later — brutally shot an MIT police officer in the head and later engaged in a shootout with police officers. Tamerlan died during the violent confrontation with police.

“I wouldn’t hesitate to seek the death penalty for Tsarnaev,” said former veteran federal prosecutor Brian T. Kelly, who is now with Nixon Peabody. “It’s totally appropriate.”

Michael J. Sullivan, a Republican who served as US attorney in Boston from 2001 to 2009 and is in favor of the death penalty, estimated that half the prosecutors in the office during his tenure were against the death penalty, though only 10 or 20 percent would go so far as to flatly refuse to take on a capital case.

He said some prosecutors who oppose the death penalty might, when faced with unusually depraved crimes, make an exception and see it as part of their prosecutor’s oath, which includes to “faithfully discharge the duties of the office.”

Sullivan, now with the Ashcroft Law Firm, said he recalled some supervisors declining to be part of death penalty review committees, and at least one prosecutor refusing to take a case to trial, all because of opposition to capital punishment. One of Sullivan’s first assistants, Gerry Leone, a former Middlesex district attorney now with Nixon Peabody, also recalled “differences of opinion on the death penalty” for all of the potential capital cases in his tenure, though he like many others interviewed declined to publicly name those who raised moral reservations.

William M. Welch II, a former federal prosecutor who agreed to argue for the death penalty in the Gilbert case, said many attorneys don’t realize, until they are deep into a case, that the death penalty will be authorized. Some stepped out at different stages along the way.

He said his decision to stand before jurors and argue for the death penalty for Gilbert was a powerful moment that he remembers “like it was yesterday” even though it was more than a dozen years ago.

“It is incredibly sobering,” said Welch, now associate chief counsel for Cigna, a global health services firm near Hartford. “It is difficult to get up . . . and ask jurors to make this incredibly serious decision. I can’t describe it.”

Ultimately, the jury chose against the death penalty, and Gilbert is now serving life without parole. Welch said he was “totally empathetic” with the jurors’ profound dilemma and felt ultimately he did the best he could on behalf of the victims.

George Vien, a former longtime federal prosecutor, said he happily agreed to help prosecute — and pursue the death penalty — for Gary Lee Sampson, a hardened criminal from Abington who later pleaded guilty to the 2001 carjacking and gruesome murder of three people. He said taking on the death penalty case “was not an agonizing decision.”

“It’s about the ultimate punishment for someone who richly deserves it,” said Vien, now practicing at Donnelly, Conroy and Gelhaar.

A jury in 2003 voted in favor of the death penalty for Sampson, but the decision was vacated in 2011 when a judge found that a juror had withheld relevant information during the screening process. A retrial of the death penalty case against Sampson is expected later this year.

Another federal death penalty case in the state was dropped before it went to trial. In 2002, two reputed Dorchester gang members involved in drug trafficking were indicted for murder charges and faced possible death sentences if convicted, but the case was dropped by the office in 2006. Criminal charges were later pursued in state court, where there is no death penalty.

Through the US attorney’s spokeswoman, the prosecutors in the Tsarnaev case have declined to talk about their involvement and have repeatedly declined to speak to the media while the case is active.

They have varied backgrounds: Weinreb, 53, a graduate of Wesleyan University and Harvard Law School and deputy chief of the antiterrorism unit, gave the prosecution’s opening statement; Chakravarty, 42, is a graduate of Johns Hopkins University and Emory Law School who prosecuted past terrorism cases and also works on a special project to improve law enforcement relationships with Muslim communities; Pellegrini, 61, is a graduate of the University of North Carolina and Union University’s Albany Law School, who has headed the office’s major crimes unit and has a special interest in wildlife protection and environmental law; and Mellin, 52, a federal prosecutor specializing in death penalty cases, is based in Texas and is assisting as part of the Justice Department’s Capital Case section.

Even the staunchest critics of the death penalty can be swayed at times by overwhelming evidence of depravity and cruelty, and this appears to be the case with Attorney General Eric Holder.

His office, by law, makes the final decision about whether to authorize the death penalty for a federal defendant, and despite his own personal opposition to capital punishment, Holder chose in January 2014 to authorize the death penalty in Tsarnaev’s case.

“The nature of the conduct at issue and the resultant harm compel this decision,” he wrote.

Ortiz, the US attorney, has said she supported Holder’s decision, and in a court submission about seeking the death penalty referred to Tsarnaev’s long list of heinous crimes and his “demonstrated lack of remorse.”

If the jury finds him guilty and, in a second phase of the trial, votes unanimously for the death penalty, Tsarnaev could be the first convict in Massachusetts to be executed since 1947, when a pair of gangsters — Philip Bellino and Edward Gertson — were convicted of first-degree murder of an ex-Marine.

These death penalty cases in Massachusetts will always be “outliers,” said John Pucci, a former federal prosecutor who is now with Bulkley Richardson in Springfield, and has written extensively against the death penalty.

These cases are sought infrequently in this state, he said, and raise “extraordinary moral and ethical” issues for those prosecutors involved.

“This is a career case that will define many of these people in their professional lives,” he said.

Patricia Wen can be reached at patricia.wen@globe.com. Follow her on Twitter @globepatty.