Outside the Manhattan criminal courthouse on Monday, a scuffle broke out among demonstrators, their chants amplified over bullhorns.

On one side were supporters of Daniel Penny, a former Marine who was charged with fatally choking a fellow subway rider, Jordan Neely, on an uptown F train last year. They held signs, including one that said, “Daniel Penny deserves a prize not a prison.” On the other side were people protesting on behalf of Mr. Neely. Upset, they grabbed a sign and ripped it up.

As the sides exchanged barbs and police officers erected a barrier to separate them, inside the courthouse 12 New Yorkers were coming to a unanimous decision. Mr. Penny, they concluded, was not guilty.

If the death of Mr. Neely, a 30-year-old homeless man who had struggled with mental health problems, had left New Yorkers unnerved and divided, the verdict quickly became yet another flashpoint in the nation’s debate over how best to address issues of crime and justice, homelessness and mental illness.

Republican political figures including Vice President-elect JD Vance, Donald Trump Jr. and former Mayor Rudolph W. Giuliani praised the jury and criticized the district attorney, Alvin Bragg, for pursuing the case.

“Thank God justice was done in this case,” Mr. Vance said on social media. “It was a scandal Penny was ever prosecuted in the first place.”

We are having trouble retrieving the article content.

Please enable JavaScript in your browser settings.

Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.

Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.wjslot

• in
• wjslot
• Penny
• Verdict
• Flashpoint