"This was very obvious, at least from the perspective of the Chinese community, that Officer Liang was made out as a scapegoat," Doug Lee, one of the organizers of the Greater New York Coalition to Support Officer Liang, told NBC News.

The police said it does not provide crowd estimates, but Lee said a police escort at the rally told him there were between 1,800 and 2,000 protesters in attendance, most of them Chinese American.

Sunday's rally, which was planned last month, came just two days after another controversial police shooting in Madison, Wisconsin, in which a 19-year-old black man was killed by a veteran police officer who is white. The shooting, which touched off a wave of protests in Madison, was still under investigation.

To help spread word about Sunday's rally in Lower Manhattan, organizers and participants said they relied on social media, including Facebook and WeChat, a mobile text and voice messaging application popular among Chinese. Most who participated, Lee said, were from states along the East Coast, including Connecticut, New Jersey, Massachusetts, Pennsylvania and New York.

Lee added that at least 50 national Chinese-American associations, including some from California and Texas, have also given their support.

"This time, while we only got 2,000 people on the ground, we actually have a lot more people involved in the movement," said Lee, who served as former chairman of the Chinese Cultural Association of Long Island and ran unsuccessfully for the New York State Assembly last year.

New York's Chinese community has been divided over the February 10 indictment of Liang, who is accused of firing the single shot that killed Akai Gurley, as he and his partner patrolled a darkened stairwell in a Brooklyn housing project.

Some Chinese Americans have said that the Chinese community should not support Liang just because he is Chinese American. In agreement with them is Margaret Chin, the Chinese-American city councilmember who represents Lower Manhattan. She had been particularly vocal in pushing for an indictment, saying that Liang needs to go through the judicial process and be held accountable for his actions.

But others, including Chinese Americans at Sunday's rally, believe that Liang has been made a scapegoat for white officers not indicted in police incidents last summer, in which unarmed black men were killed. They include Eric Garner, a Staten Island man placed in a chokehold, and Michael Brown, a teenager shot by police in Ferguson, Missouri.

"To the community it was a total slap in the face, total humiliation," Lee said of the indictment of Liang. "The entire community feels for this immigrant family."

At the rally, some demonstrators held aloft signs calling the shooting an accident, a term New York Police Commissioner William Bratton used during a November 21 press conference to describe the discharge of Liang's weapon.

But Cathy Dang, the executive director of the Committee Against Anti-Asian Violence, a Chinatown organization that addresses police and hate violence toward Asian immigrants, said that all police officers involved in incidents in which someone is killed should be held accountable, regardless of whether it was "perceived" to be an accident.

"At the end of the day, it's about life, about valuing life and humanity," said Dang, who, like Chin, supports the indictment. "Someone's life was taken. It was stolen from a family."

Lee said that in the coming months, his coalition plans to hold additional rallies in support of Liang, adding that he hopes to gain the support of Jewish-American and Asian-American organizations, including those that represent Koreans and Indians.

Lee also said he planned to reach out to groups in the African-American community.

"I do feel a good part of that community is in sync with us," he said. "My understanding is that based on the sentiment I saw expressed in the papers, most understand that it was an accident."