Jury selection kicks off Monday in the lightning-rod trial of Daniel Penny, the former Marine charged with fatally choking homeless subway busker Jordan Neely on a crowded Manhattan train car.

Groups of New Yorkers will face a series of questions — and be grilled about their own experiences riding city subways — before 12 Manhattanites are ultimately chosen to decide the fate of Penny, 25, who is charged with manslaughter and criminally negligent homicide in the caught-on-camera killing.

The May 1, 2023 tragedy sparked a firestorm over whether Penny’s actions were justified when he confronted the unarmed homeless man — who some witnesses say had been ranting in an “insanely threatening” way — on a northbound F train as it neared the Broadway-Lafayette platform just after 2 p.m.

Penny was cut loose by police on the night of Neely’s death, but was arrested two weeks later after cellphone video of the fatal chokehold surfaced online and drew outrage.

Manhattan District Attorney Alvin Bragg’s office has accused Penny of “recklessly” causing Neely’s death by choking him for more than six minutes — well past the point where Neely had stopped “purposeful movement.” 

The chokehold also continued after the subway car’s doors had opened, allowing terrified passengers to flee the scene, and after two more men began restraining Neely as well, prosecutors say.

Penny’s lawyers have argued that he is being “persecuted” for what they say was him protecting his fellow straphangers from a raving Neely, who had yelled at some point, “someone is going to die today!”

But Neely was unarmed at the time — carrying just a muffin in his pocket, video of the scene shows — and other witnesses reported not feeling like Neely truly planned to hurt anyone.

“For me, it was like another day typically in New York,” one bystander told the grand jury.

Penny has pleaded not guilty to the two charges he’s facing, which together carry a maximum sentence of 19 years in prison if he’s convicted.

Witnesses at what’s expected to be a six-week-long trial are set to include the detectives who interrogated Penny on the night of Neely’s death, and bystanders who were on the subway at the time.

It’s not yet clear whether Penny, who is out on $100,000 bail, will testify in his own defense.

Penny’s lead attorney, Thomas Kenniff, ran against Manhattan DA Bragg as a Republican in the November 2021 election. Bragg, a Democrat, won with 83 percent of the vote.