Deputy First Minister Martin McGuinness and Chief Constable George Hamilton have shared the stage at a west Belfast festival event on Thursday night.
It is believed to be the first time a Sinn Féin leader and police chief have shared a platform in Northern Ireland.
Mr Hamilton emphasised the need for courage to deal with Northern Ireland's troubled history.
He also acknowledged there had been failings in policing in the past.
"Just because I am the chief constable does not mean that I am not prepared to accept that there were serious problems in policing in the past," he added. "I do."
He said "ombudsman after ombudsman" had "shown there were serious issues and shortcomings within policing".
However, he said they "neglect to tell a much wider story of policing - a story of bravery, of courage, of pain, loss and grief".
Mr Hamilton said the current "piecemeal" way of dealing with the past was not working.
"Fear does not make peace - courage, optimism, belief is where peace is made," Mr Hamilton said.
"I think we need to be brave and courageous, easy words to say. I think we need to believe in our ability to continue to build a safe, confident, peaceful society together.
"To do so we have to face our fears, to go beyond our comfort zones, to be selfless, to be generous, to be gracious, to be ready to listen to each other and to have challenging and respectful conversations."
Mr McGuinness acknowledged his former role in the IRA and praised Mr Hamilton for attending the event.
He said republicans had to contribute to the proposed truth recovery mechanisms for those bereaved during the Troubles.
"Tonight is another act of reconciliation," he said.
"I think George Hamilton is as passionate about the peace process as I am. I think he also knows, like I do, that there are huge challenges ahead - not just for the police, or state forces, or the British government, but there are huge challenges for republicans also.
"Because republicans too, if people are to learn the truth about what happened during the conflict, will have their particular unique contribution to make. As a republican, I am prepared to make that contribution."
More than 100 people protested outside the event at St Mary's University College on the Falls Road on Thursday night.