By David Ingram
WASHINGTON (Reuters) - Retired Supreme Court Justice John Paul Stevens prodded Congress on Monday to act and presidential candidates to speak out on gun control at a time when gunmen are carrying out mass killings across the United States.
Stevens, 92, spoke to a luncheon hosted by a gun-control lobbying group where he referred to shootings such as a July rampage that killed 12 people in a Colorado movie theater.
"The fact that Congress doesn't address it is, I think, mind-boggling," he said, given the importance of the issue and the passion surrounding it.
Stevens had a leading role in two gun rights cases near the end of his 35 years on the high court. In 2008 and 2010, he dissented when narrow court majorities said individuals had a fundamental right to "keep and bear arms."
The Second Amendment to the U.S. Constitution, which the court read to guarantee the right, was intended to apply only to state-run militias, Stevens wrote.
Stevens was asked after his speech whether his criticism of Congress extended to the presidential race in which President Barack Obama and Republican challenger Mitt Romney rarely discuss guns. Stevens said he would like to hear the candidates discuss the subject more.
"That's a question I'd like to ask both of them," Stevens told reporters, quickly adding that he is no expert on running a presidential campaign. Elections are on November 6.
The inaction on gun measures reflects the strength of gun rights groups such as the National Rifle Association. Known for marshaling thousands of committed activists nationwide and running challengers against opponents, gun rights activists have blocked new restrictions in Congress since the 1990s.
Stevens left the Supreme Court in 2010 but continues to give speeches and interviews. He wrote a book published in 2011 about the five chief justices he knew during his career.
His speech on Monday doubled as a pep talk for the host - Brady Center to Prevent Gun Violence, the largest U.S. lobbying group for gun control - as he told supporters that the Supreme Court's decisions left some room for new gun measures.
The court in 2008, in the case District of Columbia v. Heller, recognized as valid longstanding rules such as bans on felons buying guns and on short-barreled shotguns.
"The failure of Congress to take any action to minimize the risk of similar tragedies in the future cannot be blamed on the court's decision in Heller," Stevens said.
(Editing by Howard Goller and Mohammad Zargham)