Washington (CNN) Martin O'Malley , the former Baltimore mayor and potential Democratic presidential contender, accepted responsibility for implementing tough policing policies that many critics say have contributed to incidents like the recent death of Freddie Gray.

Gray was a 25-year-old African-American man who suffered severe injury while in Baltimore police custody that lead to his death.

"We're all responsible," O'Malley told CNN's Jake Tapper in an interview on "The Lead." "I was responsible when I decided to run for mayor in 1999 and I told people all across our city, 'Vote for me and together we will not only improve the policing of our streets, we'll improve the policing of our police, we'll expand drug treatment and we'll save a lot of young lives by intervening earlier."

O'Malley said that when he took office Baltimore had been "the most violent and addicted city in America," and defended his policies as successful.

O'Malley rose to prominence as a tough-on-crime mayor who used data and analytics to tackle everything from drugs and murder to basic city services. He also implemented a zero-tolerance policing strategy, in which even minor offenses are vigorously prosecuted.

On his watch, he said, Baltimore "went on to achieve a record reduction in violent crime."

"(There are) probably now 1,000 mostly young, poor African-American men who did not die violent deaths in our city" because of his policies, O'Malley said.

But those policies in Baltimore and elsewhere have drawn criticism in the wake of Gray's death under unknown circumstances in police custody.

The incident was the latest in a long line of deaths of African-American men at the hands of police that have inspired a nationwide debate over police treatment of minorities and criminal justice reform, and it sparked violent riots throughout the city over the weekend.

O'Malley, who also served as governor of Maryland, cut short a trip to Ireland come back and address the unrest. He said that the events of the past week are a "setback," and described the situation as "one of our darkest days."

But O'Malley pushed back against criticism of his tough-on-crime policies as mayor, arguing that his successful elections and reduction in crime in the city proved his policies were both popular and worked.

He acknowledged, however, that achieving "balance" in a city's response to crime is tough.

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"Look, every mayor, I think, tries to get the balance right," he said. "I never once in my years as mayor ever had a single leader of a community, black or white, ever say to me, 'Mr. Mayor, I want less police presence in my neighborhood."

The former governor is expected to launch a presidential bid in the coming months, but declined to weigh in on comments from potential GOP rival Rand Paul that he was glad his train didn't stop in Baltimore, saying only that what GOP candidates for president say is "their choice."

But he did sideswipe Hillary Clinton, the heavy favorite for the Democratic Party nomination.

"Differently than Secretary Clinton, I've actually had experience on the ground making police departments more transparent and open," he said.

Still, O'Malley argued that the real issue uncovered by the series of deaths and subsequent unrest in communities across America isn't flawed policing policies -- it's that "America is failing America," and the economy is to blame.

"There's something deeper going on in this country and that is the anger, the seething anger that people feel when they're working harder, falling further behind, when they're marginalized by a brutal economy, when they see no hope for themselves, no hope for their kids. And this is not the way our country's supposed to work," he said.

"Yes, the touchstone, the flashpoint here is the tragic death of Freddie Gray, and law enforcement and race," he said. "But it's deeper than that. And that's what we need to face up to as a nation, and have a larger conversation, even as we do these individual cases the justice that Freddie Gray's life deserves."