The death earlier this month of Jordan Neely, a Michael Jackson impersonator who often performed on the train, sparked outrage after it was caught on camera.

It brought into sharp focus two burning issues in America's biggest city -- mental illness among those living on the streets, and residents' fears for their safety on the underground.

Daniel Penny turned himself in around 8:00 am (1200 GMT) and is due to be arraigned in a state court in the afternoon.

The 24-year-old is to be charged with manslaughter in the second degree, a spokesman for Manhattan District Attorney Alvin Bragg said late Thursday.

The charge accuses Penny of "recklessly" causing the death of 30-year-old Neely, but it stops short of saying he had intent to kill.

If convicted, Penny could spend up to 15 years in prison.

The death on May 1 angered activists and left-leaning lawmakers, and sparked several protests calling for the arrest of Penny.

The video showed Neely on the ground of a subway train as Penny appears to hold him around the neck for several minutes in front of a few onlookers.

Witnesses said the serviceman allegedly restrained Neely after the latter was screaming at passengers for food and drink and said he was willing to die.

Neely was reportedly not physically threatening anyone.

Family and friends told local media that he had a history of mental illness, like many living on the streets in the city of almost nine million residents.

Reports said Neely had been arrested dozens of times and that his mother had been murdered when he was a teenager.

Mental health and homeless activists said the city had failed Neely. Left-wing congresswoman Alexandria Ocasio-Cortez of New York said Neely had been "murdered."

The incident also had a racial element -- Neely was Black and Penny is white.

Protesters -- including some who spilled onto subway tracks last weekend, sparking several arrests -- decried Neely's death as an example of white "vigilantism."

Some social media users said they were scared to take New York's underground and praised Penny for intervening, but many condemned the level of force used.

The city's medical examiner said that Neely was killed by "compression" of the neck, and ruled the death a homicide.