Diving into the debate over police use of force, Democratic presidential hopeful Hillary Clinton on Wednesday urged police departments throughout the country to use body cameras and urged an end to excessive prison sentences that burden black communities.

In a speech at New York's Columbia University, Clinton called on America "to come to terms with some hard truths about race and justice" in the aftermath of this week's Baltimore riots.

"There is something wrong when a third of all black men face the prospect of prison during their lifetimes," said Clinton, the front-running Democrat in the 2016 race for the White House.

The former U.S. senator called on Congress to help "end the era of mass incarceration," tapping into growing bipartisan efforts in Washington to lower America's sky-high rates of imprisonment.

Criminal justice reform is emerging as a rare point of agreement between Democrats and Republicans. Clinton praised Republicans, including Senator Rand Paul of Kentucky, one of her rivals for the presidency, for promoting the issue.

Clinton addressed the violence in Baltimore, where rioters looted stores and burned buildings to the ground on Monday after the funeral of a 25-year-old black man who died after suffering injuries while in police custody.

"There is something wrong when the trust between law enforcement and the communities they serve breaks down as far as it has in many of our communities," Clinton said.

She said body-worn cameras for police should be "the norm everywhere."

"That will improve transparency and accountability; it will help protect good people on both sides of the lens."

Requiring police to wear body cameras has been one of the issues in the debate over policing tactics following the killing of black men by white officers in Ferguson,Missouri, and New York, among other places, last year.

In recent weeks, bipartisan efforts in Congress to lower the United States' rates of incarceration - often described as the highest in the world - have gathered pace.

Rand Paul is the co-author of a bill known as the REDEEM Act that would encourage states to keep children out of the adult justice system and allow adults with nonviolent offenses to expunge their criminal records. He argues that the United States cannot afford to keep so many people in prison.

Another bipartisan bill is aimed at reducing the number of inmates in federal prisons partly through education programs.

The chairman of the Senate Judiciary Committee, Iowa Republican Chuck Grassley, said this week that he is ready to address some justice reform issues but ruled out across-the-board cuts in mandatory minimum sentences.

In her speech, Clinton linked high incarceration rates with a lack of investment in mental health treatment services for Americans.

"Our prisons and our jails are now our mental health institutions," she said.