A video has emerged of the NYPD killing a 400-pound asthmatic man after putting him in a chokehold while attempting to arrest him on Thursday.

The video shows an NYPD plain-clothes officer confronting Eric Garner, a 43-year-old father of six, outside a Staten Island beauty supply store. Soon after Garner objects to being handcuffed, telling the officer not to touch him, another officer puts him in a chokehold. Several other officers quickly descend on him and push him to the ground, slamming his head on the concrete.

"Every time you see me you want to mess with me," Garner told cops in the video. "I'm tired of it. It stops today!"

When Garner refused to put his hands behind his back, and asked one officer not to touch him, two others moved in to make the arrest.

Garner says, "I can't breathe!" over and over as police continue to hold him down. Soon after, he stops speaking.

"They jumped him and they were choking him. He was foaming at the mouth," Ramsey Orta, the man who shot the video, told the New York Daily News. "And that's it, he was done. The cops were saying, 'No, he's okay, he's okay.' He wasn't okay."

"They were choking him. He kept saying, 'I can't breathe, I can't breathe! Get off of me, get off of me! I didn't hear any more talking after that," eyewitness Valencia Griffin told The New York Daily News. "He died right there."

The NYPD said in a statement Friday that Garner had a heart attack when police attempted to arrest him, and that they were opening up an investigation into his cause of death.

Police allegedly were trying to arrest Garner for selling untaxed cigarettes, which he had been arrested for before, although eyewitnesses said it was because he was seen trying to break up a fight. Another witness said Garner was "absolutely not selling cigarettes," Staten Island Live reported.

Now, his family is demanding accountability from the NYPD.

Those who knew Garner described him as a "gentle giant" and "a big teddy bear," according to the publication. His family members, including his wife Esaw Garner, said her husband suffered from chronic asthma.

Police told The AP that an investigation into his death is ongoing. The NYPD said Garner "took a fighting stance" and "absolutely resisted arrest."

In 1993, then- police Commisioner Ray Kelly banned the use of chokeholds by officers.

From the 2004 NYPD Patrol Guide: "Members of the New York City Police Department will NOT use chokeholds. A chokehold shall include, but is not limited to, any pressure to the throat or windpipe, which may prevent or hinder breathing or reduce intake of air."

At a memorial for Garner Thursday night, family members, friends, and supporters asked for justice.

"Is this cop still going to be on the force?" one woman asked SI Live. "Is this cop still going to be able to do this to somebody else?"

Community residents are attempting to organize a march on Friday.

New York Mayor Bill de Blasio, who has promised an investigation, expressed his condolences on Twitter today.

"@BilldeBlasio On behalf of all New Yorkers, I extend my deepest condolences to the family of Eric Garner."

Mayor Bill De Blasio has also released an official  statement regarding the death of Garner.

"On behalf of all New Yorkers, I extend my deepest condolences to the family of Mr. Garner, who died yesterday afternoon while being placed in police custody. We have a responsibility to keep every New Yorker safe, and that includes when individuals are in custody of the NYPD. That is a responsibility that Police Commissioner Bratton and I take very seriously. We are harnessing all resources available to the City to ensure a full and thorough investigation of the circumstances of this tragic incident. The NYPD's Internal Affairs Bureau is working closely with the Office of the Richmond County District Attorney, which is leading this investigation."