A high-profile priest has described Michelle O'Neill's decision to attend a police recruitment drive as "a milestone", adding that "it paves the way for the normalisation of society in Northern Ireland".
Father Martin Magill was speaking after the Sinn Fein Deputy First Minister appeared at Tuesday's event at the policing college in east Belfast, alongside colleague Gerry Kelly, the party's policing spokesman.
It is the first time a senior Sinn Fein figure has attended a PSNI recruitment campaign.
Fr Magill praised both Mrs O'Neill and Mr Kelly for turning up at Garnerville for the launch event to recruit 600 officers.
The move comes amid ongoing concerns that progress to address under-representation of Catholics in the force has stalled and is starting to go in a backward direction.
Mrs O'Neill joined DUP First Minister Arlene Foster as they posed with Chief Constable Simon Byrne in holding up posters promoting the PSNI as a "positive career choice".
Fr Magill, who is credited with galvanising local politicians and the British and Irish Governments into restarting the Stormont talks, said it was a "very significant" move that "takes us into a new territory".
"I was surprised to see Michelle O'Neill and Gerry Kelly walking into the room," he said.
"But that was quickly eclipsed by a very real sense of satisfaction. I made a point of thanking them both for doing this and they acknowledged me.
"This takes us somewhere new. It's a milestone. And it means we are beginning to normalise policing here, and that has to be welcomed."
Fr Magill, whose rousing speech won him a standing ovation at Lyra McKee's funeral, also voiced his support for the campaign and encouraged "anyone who feels a vocation to policing" to sign up.
Sinn Fein had previously been accused of not doing enough to advocate policing as a career, and Mr Byrne said the appearance of Mrs O'Neill yesterday was "seismic and historic".
Dissident republican targeting of Catholic officers is a key factor in the falling numbers of applications from the nationalist community here. Mr Byrne, who had urged nationalist and republican leaders to be more vocal in promoting the police, said: "We have called for that support in the past and now people have stood up to that challenge and stepped forward and are encouraging people to join the PSNI, so I think it's an historic day not just for policing but for Northern Ireland."
Mrs O'Neill said she wanted a police service that was more representative of the community it serves, adding that she wanted to see a return of the controversial 50:50 policy that ensures the PSNI recruits Catholics and Protestants in equal numbers.
"Clearly the PSNI have launched a very significant, intensive recruitment campaign and we are here because it is no secret that nationalists are under-represented in the police service, that Catholics are under-represented in the police service and, if we are going to have a police service that commands community confidence, then it needs to be reflective of the community it serves, so we are here because of that reason," she said.
DUP leader Mrs Foster welcomed the move and said it was the "next step" in Sinn Fein's journey in supporting the police.
"I think it is important because there have been a lot of conversations about the fact that we need to have a police service that reflects Northern Ireland society, so I think it's important that, as leaders, we show leadership and come along to these events to support our police service, so that is significant and I very much welcome it," she said.
Former Assistant Chief Constable Peter Sheridan, who was the highest-ranking Catholic policeman in Northern Ireland, said Mrs O'Neill was "making a particular point" by attending in person, adding that it would help maintain the number of Catholic officers in the PSNI.
"A representative police service is in everyone's interest in this society, it doesn't matter whether you're Catholic or Protestant," he said.
"Whether it's political parties or civil society, people should be supporting policing because that's what delivers safer communities and improves people's lives in communities.
"The police service should be owned by every community, so a critical part of that in nationalism and republicanism is demonstrating that visible support in leadership terms for good policing."