– The death penalty continued its slow and steady two-decade decline this year, as fewer convicted murderers were sentenced to die and most executions were limited to just three states, according to a report scheduled for release Thursday.

The number of new death sentences plummeted from 315 in 1996 to 72 as of Wednesday, according to the Death Penalty Information Center.

The number of executions carried out has fallen sharply as well. This year, 35 convicts were put to death, compared with 98 in 1999. And whereas 20 states were carrying out executions in the 1990s, only seven did so this year.

“The relevancy of the death penalty in our criminal justice system is seriously in question when 43 out of the 50 states do not apply the ultimate sanction,” said Richard Dieter, the center’s executive director.

Most of the executions took place in Texas (10), Missouri (10) and Florida (8). The other states to carry out executions were Oklahoma (3), Georgia (2), Arizona (1) and Ohio (1).

Even in Texas, the number of new death sentences has fallen sharply, from 48 per year in the late 1990s to fewer than a dozen per year recently.

Experts say the trend reflects a steep drop in violent crime, a growing use of “life without parole” sentences for convicted killers and a skepticism over the death penalty itself.

Nationwide, there were about 10,000 fewer murders in recent years compared with the 1990s. The FBI reported 24,526 murders in 1993; last year there were 14,196.

Some prosecutors pursuing a murder case don’t seek the death penalty because of the high cost of litigating such cases. Others are deterred by the need for absolute proof.

“DNA confirmed there were a lot of innocent people on death row, and judges and juries have become more cautious as a result,” Dieter said.

Another key factor is the growing reliance on life-term prison sentences that include no option for parole. In the 1980s and beyond, jurors often said they decided in favor of a death sentence because they feared a murderer who was sentenced to “life in prison” would be released on parole in a decade or two. But since the 1990s, every state has allowed for life terms in prison with no possibility of parole.

Faced with that option, many jurors vote for a life sentence rather than death.

Kent Scheidegger, counsel for the Criminal Justice Legal Foundation in Sacramento, said the drop in death sentences reflected the decline in murders. “The murder rate today is a bit more than half what it was in the mid-90s,” he said.

He also said prosecutors were concentrating on the most aggravated murders. “In years past, you would sometimes see death sentences for simple cases of robbery-murder. You don’t see that much any more,” he said. “When you read of a new death sentence being rendered today, it is typically for a particularly horrific murder, which is exactly how the system is supposed to work.”