"I would do stop-and-frisk. I think you have to," Trump said, according to excerpts of a Fox News "town hall" in Cleveland, after a listener asked what he would do to reduce crime in predominantly black communities across the nation.
"I see what's going on here, I see what's going on in Chicago, I think stop-and-frisk. In New York City it was so incredible, the way it worked," he added.
Ending the practice in New York was a key plank of Democrat Bill de Blasio's successful 2013 run for mayor.
As the race between Trump and Democrat Hillary Clinton tightens ahead of the Nov. 8 election, he has been reaching out to African-American voters, shown by opinion polls to largely favor Clinton.
Trump has portrayed himself as the "law-and-order candidate." But Clinton has criticized many of his proposals as unconstitutional attacks on American freedoms.
Clinton's campaign did not immediately respond to a request for comment on Trump's statement.
"Stop and frisk" had saved lives and reduced crime in New York City under Giuliani, the Trump campaign said in a statement.
"Mr. Trump believes that a locally tailored version of 'stop and frisk' should be used in Chicago to help reduce skyrocketing violence and make our Chicago safe again," spokesman Jason Miller said.
'We are victims'
Anger over police tactics has risen as their fatal encounters with African-Americans, many of them unarmed, have sparked protests and unrest across the country.
In his appeal to African-American voters, Trump has lamented the woes of black communities, asking those who traditionally vote Democratic to take a chance on him. But his often dire portrayals of their lives have left some black voters unmoved.
Connie Tucker, a pastor at Father Heart Ministries in Columbus, Ohio, said she liked policies that brought results, so if stop-and-frisk helped cut crime, she backed it.
But Tucker, who is white, said she sensed discomfort in the room at Trump's remarks. "I felt like there was a pause," she said.
Another attendee, Geoff Betts, 38, who is black, said he felt dismayed by Trump's response.
Betts, a hair products distributor, said he was registered to vote as an independent and attended to learn how Trump would try to win over black voters.
He said he thought police unfairly discriminated against black citizens and that he opposed stop-and-frisk.
"We are victims," he said, adding that he had walked out of the meeting. "I just couldn't take it anymore, I had to go. I don't think that Donald Trump gets it."