Chinese Americans are petitioning on a White House website for the cancellation of an indictment against a Chinese-American police officer in New York, whose gunshot killed an African-American man.

The petition, posted on Feb 17 at "We the People", demanded that the Obama administration ask Brooklyn District Attorney Kenneth Thompson "to withdraw indictment against Asian minority officer Peter Liang".

The White House will respond to any petition that reaches 100,000 signatures within 30 days; the threshold was reached in less than a week. People share links to the "We the People" website through WeChat, an instant-messaging app similar to Line that is popular among Chinese communities globally. As the judiciary system is independent from the executive branch, petitioners actually expect little from the White House and don't believe the indictment will be withdrawn.

According to numerous reports, Liang was patrolling a Brooklyn public housing complex on Nov 20 when he drew his weapon in a darkened stairwell. The gun discharged, and the ricocheted shot struck and eventually killed Akai Gurley, 28.

Liang, 27, who had fewer than 18 months on the force, was indicted by a grand jury on six charges, including second-degree manslaughter, and could face a prison term of up to 15 years.

The petition claimed the indictment is for "political gain" and Liang "becomes [a] scapegoat." It echoed speculation not only in Chinese communities but also in mainstream publications that the indictment is connected to the cases of Michael Brown in Missouri and Eric Garner on Staten Island, New York.

Both cases involved unarmed African-American men killed by police officers in the summer. The lack of an indictment in the cases sparked nationwide protests and raised tensions between police and ethnic minorities.

"I have been living in America for over 20 years, but it is the first time that I have seen such a petition," said Lantao Sun, a New York-based civil lawyer. "Thanks to WeChat, the petition message was spread to Chinese communities all over New York and showed the power we have when we are united."

"We do this for public attention and a chance for equality, so that Liang wouldn't be a scapegoat," said Hui Guan, who works in the insurance industry in Atlanta, Georgia.

While some Chinese Americans do support the indictment, many fear he would be sacrificed and face a biased trial, as Asian Americans lack the political representation of other ethnic groups.

The political mobilization of this scale among Chinese Americans used to be rare, said Xiangxi Liu, a federal detective in Columbus, Ohio, and a former US Army sergeant.

"Past generations of Chinese wanted to become part of the US society so much that they even started to belittle themselves," Liu said. "In return, they only see injustice and unfairness. Now, younger generations of Chinese Americans decided to say no."

"We should really credit technology to these movements," said Wenhong Xie in San Jose, California. He is running Civil Rights, an account on WeChat sending political articles to thousands..

In October 2013, Chinese Americans protested ABC talk-show host Jimmy Kimmel for airing comments by a child who said "killing everyone in China" would help solve America's debt problem, resulting in an apology by Kimmel.

In 2014, Chinese Americans protested Senate Constitutional Amendment 5 (SCA-5) in California. It considered race a factor in state university admissions and could have resulted in qualified Chinese Americans being rejected because of their race. The SCA-5 was withdrawn.

"Technology, for example WeChat, makes collaborations easier," Xie said. "Even if we did not have a national organization, we could still do things together."

Lu Huiquan and Hong Xiao in New York contributed to this story.