By Arun Kumar 

Washington, Nov 26 (IANS): Angry demonstrators chanted and marched through the streets of Chicago for a second day as a graphic video of a white police officer shooting a black teenager 16 times left President Barack Obama "deeply disturbed".

The protests over the shooting of 17-year-old Laquan McDonald by Chicago police officer Jason Van Dyke on October 20 last year, however, were peaceful.

Van Dyke was charged with first-degree murder hours before the release of the video on a judge's orders Tuesday.

"Like many Americans, I was deeply disturbed by the footage of the fatal shooting of 17-year-old Laquan McDonald," Obama said, thanking "the people of my hometown for keeping protests peaceful".

The video shows McDonald running, then later walking down the middle of a street. He heads toward some police cars with flashing lights, then veers away.

It's then that he appears to spin around and falls, brought down by a barrage of bullets. There were 16 shots fired over 15 seconds, all by Van Dyke.

Cook county state's attorney Anita Alvarez said Van Dyke had been on site less than 30 seconds, and out of his car for six seconds, when he started shooting.

"The officer in this case took a young man's life," police Superintendent Garry McCarthy said Tuesday. "And he's going to have to account for his actions."

Beyond the video's troubling nature, the fact Laquan McDonald wasn't the first black person shot dead by a Chicago police officer was another reason that protestors took to the streets, CNN said.

At one point Tuesday night, they seemed to form a circle and chanted names of others they said were also victims of police violence in the city.

Chicago began being called the murder capital of the United States back in 2012 after it registered 503 homicides, more than any other city. The FBI's 2014 statistics showed 411 killings -- more than the 333 in New York and 260 in Los Angeles, two cities with higher populations.

Some of the city's most prominent black leaders called on Wednesday for investigations into the Chicago Police Department and its handling of the shooting, according to the New York Times.

They expressed anger and dismay toward the department's leadership, and some demanded the resignation of the police superintendent.

The calls from civic, political and religious leaders came from, among others, the Chicago Urban League, members of the black caucus of the Chicago City Council and two members of Congress.