BOSTON (AP) — The parents of the youngest victim of the Boston Marathon bombing are urging federal authorities to consider taking the death penalty off the table for the man convicted in the case.

Bill and Denise Richard, whose 8-year-old son, Martin, was one of three people killed by the April 2013 explosions at the marathon’s finish line, say in a front-page piece in Friday’s Boston Globe (http://bit.ly/1cBzoQE ) that sentencing Dzhokhar Tsarnaev to death “could bring years of appeals and prolong reliving the most painful day of our lives.”

“We are in favor of and would support the Department of Justice in taking the death penalty off the table in exchange for the defendant spending the rest of his life in prison without any possibility of release and waiving all of his rights to appeal,” they wrote.

The Richards’ daughter, Jane, lost a leg in one of the explosions, and they both suffered injuries.

“We understand all too well the heinousness and brutality of the crimes committed. We were there. We lived it. The defendant murdered our 8-year-old son, maimed our 7-year-old daughter, and stole part of our soul. We know that the government has its reasons for seeking the death penalty, but the continued pursuit of that punishment could bring years of appeals and prolong reliving the most painful day of our lives,” they said.

They wrote that when Tsarnaev fades from the media spotlight and public view they can start “rebuilding our lives and family.”

The Richards never mention Tsarnaev by name, simply calling him “the defendant,” and stressed that they are speaking only for themselves.

U.S. Attorney for Boston Carmen Ortiz says she is aware of the Richards’ view but cannot comment on the specifics.

“But as I have previously assured both Bill and Denise, I care deeply about their views and the views of the other victims and survivors,” Ortiz said.

Jennifer Lemmerman, the sister of Massachusetts Institute of Technology police officer Sean Collier who was killed by Tsarnaev and his older brother days after the explosions, has also spoken out against the death penalty on her Facebook page, in posts that have since been removed.

Relatives of other victims have expressed support of the death penalty.

When it announced its decision to seek the death penalty, the Justice Department cited the killing of a police officer, the death of a child and the choice of the Boston Marathon as a target because its huge crowds provided an opportunity for maximum bloodshed.

Robert Blecker, a New York Law School professor and death penalty expert, said it’s highly doubtful the statement by the Richards will sway the Justice Department.

“Victims and the survivors play a role — they should have a voice — but the reason they don’t get a veto and shouldn’t get a veto is because often there are larger interests at stake,” said Blecker, who said he supports the death penalty for Tsarnaev.

“The question here is one of terrorism and partly a statement of denunciation of terrorism because that is one of the purposes of the death penalty,” he said.

The penalty phase of Tsarnaev’s trial starts Tuesday, the day after this year’s marathon.