"I could stand in the middle of 5th Avenue and shoot somebody and I wouldn't lose voters," Trump said at a campaign rally here.
After the event, Trump declined to answer when asked by CNN to clarify his comments.
The GOP front-runner has repeatedly pointed to the loyalty of his supporters, many of whom tell reporters and pollsters that almost nothing could make them change their mind about voting for Trump in the presidential race.
Trump's comments come as the debate about gun violence in America has taken center stage in American political discourse amid several highly publicized mass shootings.
Trump has repeatedly touted his strong support for the Second Amendment and slammed President Barack Obama's recent use of executive orders to expand the reach of background checks needed to purchase a gun.
The brash billionaire's comments also come less than two months after two ISIS-inspired terrorists killed 14 people in San Bernardino, California
, and ISIS-linked attacks killed 130 in Paris
. In response, Trump has called for fewer gun restrictions and a harder stance on terrorism.
Asked about Trump's comment after a campaign event in Iowa, Texas Sen. Ted Cruz, Trump's top rival for the GOP nomination, shook his head.
"I will let Donald speak for himself," Cruz said. "I can say I have no intention of shooting anybody in this campaign."
Trump has joked about killing people before.
Last month, he appeared to consider whether he would kill journalists
, as Russian President Vladimir Putin -- whom Trump defended
-- has been accused of doing.
"I would never kill them. I would never do that," Trump told supporters in Grand Rapids, Michigan, before reconsidering.
"Uh, let's see, uh?" he said aloud, his voice rising. "No, I would never do that."