The first clear contrast of the debate emerged over the question of support for adding more police to the subways. Ms. Wiley, Dianne Morales, a former nonprofit executive, and Scott M. Stringer, the city comptroller, did not raise their hands when asked for a show of support, emphasizing that their focus would instead be on empowering more mental health professionals.
The debate, like many earlier mayoral forums, was held virtually — the candidates appeared by video from their homes and other locations around the city — which made it harder to smoothly land clear standout moments and more challenging to jump in given the cacophony of several people talking over each other on camera.
Throughout months of virtual forums, the candidates became familiar with each other — their policy platforms and their well-traveled lines — and developed a measure of collegiality over Zoom, with few moments of obvious tension. On Thursday, the format was similar but the stakes far higher, the audience larger and the contrasts notably sharper.
In addition to the criticisms aimed at Mr. Yang and Mr. Adams, Mr. McGuire and Mr. Donovan clashed over Mr. McGuire’s tenure on Wall Street, and Mr. Stringer took an implicit shot at Mr. Donovan, who has been bolstered by a super PAC funded in part by his father.
“Don’t get me involved in your daddy problems,” Mr. Stringer said, after Mr. Donovan noted outside groups had supported Mr. Stringer in the past.
For Mr. Stringer, the debate was his most high-profile appearance following an accusation of unwanted sexual advances that has upended his campaign. Mr. Stringer has strongly denied the allegations from Jean Kim, an unpaid campaign worker on his 2001 race for public advocate, but the claims cost him the support of some of his most prominent progressive supporters, though he retains backing from key labor endorsers. He emphasized again during the debate that he rejected the allegations.
Mr. Donovan, a veteran of the Obama administration, went after both of the leading candidates. He ripped into Mr. Adams for remarks he has made about carrying a gun, and used his extensive government and political experience to draw a sharp contrast with Mr. Yang.