Capital punishment is on the decline in the U.S.

About once a week, a convicted murderer is put to death in a state penitentiary, most often in Texas, where 11 of this year’s 12 executions have occurred.

But nationwide, capital punishment is under siege. Since the first of the year, individual states have acted on long-festering questions about the equity of the death penalty and made bold moves aimed at repealing it, slowing the practice or temporarily halting it because of rising costs.

In March, the Nebraska Legislature came within one vote of repealing its death penalty law. The new governor of Maryland called for the outright repeal of capital punishment. Most of Georgia’s 72 capital cases have been stopped because the state’s public defender system has run out of money. New Jersey lawmakers are drafting a bill to repeal that state’s death penalty. And in March the governor of Virginia, a state whose 96 executions since 1976 are exceeded only by Texas, vetoed five bills that would have expanded the use of capital punishment.

“I do not believe that further expansion of the death penalty is necessary to protect human life or provide for public safety needs,” said Democratic Gov. Timothy M. Kaine, who opposes capital punishment.

Skepticism toward and resistance to the death penalty has intensified since the late 1990s, after investigations uncovered wrongful convictions. That and existing moral objections prompted some states, led in 2000 by Illinois and then-Gov. George Ryan, to place a moratorium on executions, which have dropped from 98 in 1999 to 53 in 2006.

States have been influenced by pragmatism, with concerns over the costs of lengthy appeals, which in some cases exceed two decades. Six pending appeals of death penalty cases in Ohio, where 191 people are on death row, include cases that go back to 1984.

Pointing to multimillion-dollar appeals costs, Frank Zimring, a law professor at UC Berkeley, said: “People are starting to talk about cost and notice the marginality of the death penalty.”

Maryland Gov. Martin O’Malley, a Democrat, said 56 people had been sentenced to death in his state since 1978, and taxpayers had spent about $22.4 million beyond the cost of imprisonment on appeal litigation.

He said in February that if the state were to replace the death penalty with life without parole, “that $22.4 million could pay for 500 additional police officers or provide drug treatment for 10,000 of our addicted neighbors. Unlike the death penalty, these are investments that save lives and prevent violent crime.”

There are about 3,350 convicts on death row, and more than one-third of them -- 1,450 -- are in California (660), Florida (397) and Texas (393).

During the 1990s, U.S. courts would customarily issue about 300 death sentences annually. Those numbers have plummeted in the last seven years, to 128 in 2005 and 102 last year, according to the Death Penalty Information Center, a Washington advocacy group against capital punishment.

Efforts to repeal or otherwise rethink the death penalty do not suggest that the days of capital punishment in the U.S. are nearing an end. (Thirty-seven states have the death penalty; 12 do not and New York’s was declared unconstitutional in 2004.) Though the Montana Senate approved the abolition of the death penalty this year, a House committee defeated the measure. In New Mexico, the House approved a repeal but a Senate committee said no. In Maryland, a legislative committee rejected O’Malley’s plea to replace the death penalty with life without parole.

Furthermore, public opinion polls consistently show majority support for the death penalty. Fifty-six percent of Wisconsin voters last fall approved an advisory referendum to re-impose the death penalty in the state, which recorded its last execution more than 150 years ago.

“I don’t think the country is about to get rid of the death penalty,” said Richard C. Dieter, executive director of the Death Penalty Information Center. “But overall, the trend shows some rethinking and hesitance.”

“Because of flaws in the system and economics, everything is now being given a fresh look,” Dieter said.

Support for life imprisonment without the prospect of parole has been growing, polls show. That, coupled with questions about the application of capital punishment and concerns about mounting costs, have undermined political support for the death penalty.

Ohio Gov. Ted Strickland is an ordained minister and former prison psychologist who worked on Ohio’s death row. A Democrat, he has long been an advocate of the death penalty but now defines himself as a “supporter with certain reservations.”

“There is convincing evidence that individuals have been wrongly convicted,” said Strickland, who delayed the scheduled executions of three inmates shortly after taking office in January.

One of Strickland’s predecessors, Michael V. DiSalle, who served as Ohio’s governor from 1959 to 1963, personally investigated the cases of death row inmates while he was governor.

“The possibility of an irrevocable error was so vivid to me that on several occasions I made last-minute visits to the grim, antiquated Ohio State Penitentiary ... for a final interview with the condemned man,” DiSalle wrote in his 1965 book “The Power of Life or Death.”

Eleven states, including California, have moratoriums on executions because of questions about the lethal injection process, the most common form of execution. Nebraska, the only state to mandate use of the electric chair, may revisit the issue, with consideration of a bill allowing for life imprisonment if an inmate can be held without endangering others.