Maryland Governor Martin O'Malley and Archbishop William E. Lori urged lawmakers in Annapolis to repeal Maryland's death penalty.

Sensing a real chance to abolish the death penalty in Maryland after years of trying, opponents of capital punishment brought a parade of religious, political and civil rights leaders to Annapolis Thursday to urge lawmakers to do away with the ultimate sanction.

Roman Catholic Archbishop William E. Lori, testifying before a legislative committee for the first time since taking the helm of the Archdiocese of Baltimore last year, said he had come to Annapolis to throw the church's support behind the repeal effort.

"While those who have done terrible harm to others deserve punishment," he said, the church opposes the death penalty because it considers even the lives of criminals sacred — and because of "what it does to all of us as a society."

Gov. Martin O'Malley, who has made repeal a priority this year, and Benjamin T. Jealous, president of the NAACP, weighed in with more practical arguments: that capital punishment does not deter crime, that it is racially biased, and that new DNA analysis has exonerated a disturbing number of death-row inmates.

O'Malley also contended that it costs taxpayers more to impose a death sentence than to incarcerate a convict for life without the possibility of parole.

"The death penalty is expensive, and the overwhelming evidence tells us that it does not work," O'Malley, a Democrat, told members of the Senate Judicial Proceedings Committee.

Though outnumbered at the witness table, prosecutors, police officials and some relatives of murder victims pushed back. They argued that the death penalty should be preserved for the "worst of the worst" killers, that the public wants to keep it, and that DNA technology and new legal safeguards adopted in Maryland in 2009 have greatly reduced the chances that any innocent person would be wrongly convicted, much less executed.

"Don't you think it is true there are individuals that commit such heinous acts that they don't deserve to live in any society, even and especially in a correctional institution?" asked Scott D. Shellenberger, the Baltimore County state's attorney. He said the death penalty is not about vengeance for the murdered, but about justice.

And Rick Prothero, whose brother, Baltimore County police Sgt. Bruce Prothero, was murdered in a Pikesville jewelry store robbery in 2000, made an emotional appeal to senators to keep capital punishment.

"It is only to be used on those who have so violently violated humanity that they have no place in this world," Prothero said.

Lawmakers in the Senate panel, which has bottled up repeal bills in years past, grilled witnesses on both sides, and one or two senators indicated they are grappling with how to vote this time.

Opponents of the death penalty say a majority of lawmakers in both the House and Senate have indicated they support repeal this year. Senate President Thomas V. Mike Miller Jr. has promised to bring a repeal bill before the full Senate if the votes are there, even though he personally favors keeping the death penalty.

Thirty-three states still have capital punishment. If Maryland abolishes it, it would be the sixth state to do so in recent years. Connecticut ended it last year.

The last execution in Maryland was in 2005. The death penalty was been on hold since 2006, when the Court of Appeals found fault with state regulations for administering it. The state still has five inmates on death row, three of them for crimes committed in 1983.

The repeal bill, if it passes, would affect only future cases. Asked if he would commute the existing death sentences, O'Malley responded that he would review each case and decide it "according to the law."

Senators quizzed O'Malley and the others on whether removing capital punishment from the books might tie prosecutors' hands in getting accused murderers to plead guilty in exchange for life in prison without parole. Sen. James Brochin, a Baltimore County Democrat, noted that Maryland Attorney General Douglas F. Gansler and the state's attorneys of Baltimore and Prince George's counties oppose its repeal for that reason.

"I respectfully disagree with the attorney general on this issue," O'Malley said.

Surveys indicate that Maryland voters are divided over the death penalty. A recent Baltimore Sun poll found that 48 percent supported capital punishment and 42 percent opposed it.

Some surveys have found that many voters would favor repealing the death penalty if it were replaced by a sentence of life in prison without parole.

Death penalty supporters insisted that even though it is rarely imposed, it still poses a deterrent.