WASHINGTON (CNN) -- A day after New Jersey banned executions, newly released figures show that capital punishment dropped this year to a 13-year low.
The Supreme Court will hold oral arguments January 7 about the constitutionality of lethal injection protocols.
Forty-two people have been put to death this year, according to the Death Penalty Information Center (DPIC), a Washington-based group that opposes the practice. That figure is down 57 percent from what it was in 1999, when 98 inmates were executed.
Next year's figures are expected to drop further. The Supreme Court is to hold oral arguments January 7 about whether lethal injection protocols in 36 of the 37 states with the death penalty are constitutional. See how the rates have dropped »
The justices placed a moratorium on executions in late September, when they decided to review a Kentucky case about whether the three-drug lethal "cocktail" of chemicals represents "cruel and unusual punishment," since it may cause excruciating pain to inmates unable to express discomfort.
Stays of executions have been issued in several states until the larger constitutional issues are addressed.
If the high court finds the procedures unconstitutional, it could take years before death-penalty states would meet legal standards necessary to resume lethal injection. And even if the method is declared acceptable, it would be months before new execution dates could be set.
Ten states carried out executions this year. Outside the South, Arizona, South Dakota, Indiana, and Ohio together subjected six men to lethal injection. Learn about states' death penalty policies and statistics »
Texas continues to lead the nation, with 62 percent of executions nationwide this year. Overall, 86 percent this year were in the South.
No more executions are scheduled this year.
"The death penalty has been in a period of decline for many years," said Richard Dieter, executive director of DPIC.
"Two thousand seven will be known as the year executions came to a temporary halt and as the year of concrete legislation reconsidering the death penalty."
Death penalty supporters acknowledge that states outside the South have been reluctant to impose the punishment, even in the face of rising big-city crime rates.
"I think the main problem is that the death penalty is not being imposed often enough in those urban jurisdictions," said Kent Scheidegger of the Sacramento-based Criminal Justice Legal Foundation.
"I think people of the cities are not getting the quality of justice that people elsewhere receive. I think we need to build support for the death penalty and need to impose it more regularly where it is warranted."
New Jersey's legislature voted last week to outlaw the death penalty -- the first state to do so in 42 years -- and Gov. Jon Corzine signed the measure into law Monday. At the same time, he commuted the sentences of the eight men on the state's death row. The move was largely symbolic, since no executions have occurred there since 1963.
Similar bills in Nebraska, New Mexico and Montana failed this year in the legislature. State lawmakers in Maryland, Colorado, North Carolina, Tennessee and California are also considering abolishing the death penalty, but no bills have been introduced.
The Supreme Court on January 4 will decide whether to review an appeal from Louisiana inmate Patrick Kennedy, sentenced to death in 2003 for raping his 8-year-old stepdaughter. The state's high court upheld the punishment as appropriate.
The justices in 1976 banned capital punishment for rape, but 19 years later, Louisiana passed a law allowing execution for the sexual violation of a child under 12. State lawmakers distinguished the earlier high court case as pertaining only to "adult women." E-mail to a friend