U.S. Sen. Rick Santorum (search), a longtime death penalty supporter, said he is re-examining his stance.
"I still support the death penalty (search), but what I'm suggesting is, number one, we have to be more cautious," Santorum said Tuesday, adding that its use should be limited to the "most horrific and heinous of crimes."
He said his examination "has narrowed its application, but it's not saying that I fundamentally believe the death penalty is wrong."
In an interview published in the Pittsburgh Post-Gazette on Tuesday, Santorum said: "I agree with the pope that in the civilized world ... the application of the death penalty should be limited. I would definitely agree with that. I would certainly suggest there probably should be some further limits on what we use it for."
Asked to elaborate by The Associated Press, Santorum said: "I could see a legitimate rationale for not executing juveniles" as long as the offender was sentenced to life in prison without the chance of parole.
On March 1, the U.S. Supreme Court (search) ruled that it's unconstitutional to execute juvenile killers.
Santorum said he favors the use of DNA technology (search) to eliminate the likelihood that a person wrongly convicted would be executed.
The conservative Catholic and abortion opponent said he was moved by the call of Pope John Paul II (search) to be "unconditionally pro-life."
"Again, the Catholic Church teaches the death penalty is permissible under some circumstances," he said, but it is the pope's opinion that the death penalty has no place in a civilized society.
"This is not the taking of innocent human life ... in many respects, you could look at the death penalty as self-defense" in that it removes those who have killed, he said.
"There are reasons that we execute people: for the sake of protecting society and exacting justice" and as a deterrence, he said.
State Treasurer Robert P. Casey Jr. (search), who said he plans to seek the Democratic nomination to challenge Santorum, has been on record as supporting the death penalty.
Casey is on vacation out of the state, said campaign spokesman Mark Farinella.
Santorum has been re-examining his views at a time when recent polls find Catholics backing off support for the death penalty.
The U.S. Conference of Catholic Bishops (search), which has announced a new campaign against the death penalty, also released surveys from last November and this month showing that adult church members, once supportive of the death penalty, are now evenly divided on the issue.
A survey of 1,785 Roman Catholic adults done last November by pollster John Zogby showed 48 percent of respondents either strongly or somewhat in favor of the death penalty, with 47 percent strongly or somewhat opposed. A follow-up survey this month among more than 1,000 Catholics found 48.5 percent supporting capital punishment and 48.4 percent opposed.
The margin of error in Zogby's November survey was plus or minus 2.8 percentage points and in the March survey, plus or minus 3.2 percentage points.
Previous polls by other news organizations have found stronger support among Catholics for the death penalty.