The ranks of people sentenced to death and the number executed declined in 2004 as the nation's death row population kept shrinking, the government reported yesterday.

Last year, a dozen states executed 59 prisoners, six fewer than in 2003, according to the Justice Department's Bureau of Justice Statistics.

The report also said 125 people, including five women, who were convicted of murder received a death sentence last year. That was the smallest number since 1973.

Last year, 22 death row inmates died of natural causes or committed suicide, while an additional 107 had their sentences commuted, tossed out or overturned. As of Dec. 31, there were 3,315 people on death row, compared with 3,378 a year earlier.

Tracy Snell, one of the report's authors, said the number of prisoners under death sentences has declined four years in a row, the result of a murder rate at its lowest level in 40 years.

One death penalty advocate said the threat of harsh punishment is responsible for that decline.

"There are less murders, less murder victims and less death sentences because, in our view, we have been giving this problem the right medicine," said Michael Rushford, president of the Criminal Justice Legal Foundation in Sacramento.

"Most states have effective habitual-offender laws. These laws take the most likely group of potential capital murderers off the street," said Rushford, whose public interest law group works "to strengthen law enforcement's ability to assure that crime does not pay," according to its Web site.

Richard Dieter, executive director of the Death Penalty Information Center in Washington, said jurors increasingly are reluctant to recommend the death penalty.

He cited recent cases in which death row prisoners have been freed after media or legal investigations; the use of DNA evidence to exonerate those wrongly convicted; and the increased availability of life-without-parole sentences as an alternative to capital punishment.

"The thing that stands out to me is the breadth of the decline," said Dieter, whose group has been critical of how the death penalty is applied. "I think if it were just one year or one of those numbers, it would be less consequential. What we're witnessing is a pullback from the death penalty across the country."

Today, 37 of the 38 states with death penalty laws allow juries to consider life without parole as an alternative. That option may come to have a large effect in Texas, which in 2004 executed 23 prisoners, or more than three times as many death row inmates as any other state. A Texas law that took effect Sept. 1 allows capital murder juries to consider life without parole for convicted offenders.

California had the most prisoners on death row, with 637 inmates at the end 2004. California, Florida and Texas together account for 44 percent of the nation's death row prisoners, according to the report. In the 2000 U.S. Census, those states made up 25 percent of the U.S. population.