The three U.S. Democratic presidential hopefuls participated in a television forum Friday.
MSNBC host Rachel Maddow, in Rock Hill, South Carolina, interviewed each candidate -- Hillary Clinton, Vermont Senator Bernie Sanders and former Maryland Governor Martin O'Malley -- one at a time.
Front-runner Clinton was interviewed after the two men.
Clinton was the only one of the trio who supported the death penalty in certain cases, including for September 11, 2001, terrorist attack mastermind Khalid Sheikh Mohammed and Oklahoma City bomber Timothy McVeigh.
However, she declined to say whether the death penalty is an appropriate response in Dylann Roof's racially motivated shooting of nine African-Americans in a South Carolina church.
Sanders noted his opposition to the war in Iraq from the start -- unlike Clinton -- and his refusal to accept super political action committee donations
He said he opposes the Obama administration's recent decision to send special forces to Syria, a position Clinton supports.
O'Malley said he is proud to be a lifelong Democrat, and questioned Sanders loyalty to the political party. Sanders is an independent in Congress who generally sides with Democrats.
"I think that when President (Barack) Obama was running for re-election, I was glad to step up and work very hard for him while Senator Sanders was trying to find someone to primary him," O'Malley said. "I'm a lifelong Democrat. ... I believe in the party of Franklin Roosevelt."