Protesters angry over Chicago police shootings tried to disrupt Mayor Rahm Emanuel's annual breakfast honoring Martin Luther King Jr. on Friday.

It was the latest in a series of demonstrations since the November release of video showing a white police officer shooting a black teenager, Laquan McDonald, 16 times in October 2014. On Thursday, the city released video of a 2013 shooting in which a white officer shot and killed a 17-year-old black carjacking suspect, igniting fresh concerns.

Protesters tried to block the entrance to Friday's breakfast. One protester came into the room during the event and yelled "16 shots." Several prominent pastors said they'd boycott.

Community groups and leaders allege a cover-up in the McDonald case and there have been calls for him and Cook County State's Attorney Anita Alvarez to resign.

U.S. District Judge Robert Gettleman, during a Thursday hearing in a civil suit in federal court, lifted a protective order on the 2013 video. That came after the city -- in a surprise about-face -- dropped its longstanding opposition to making it public.

The video was taken by several surveillance cameras and from various angles. It captured at least parts of the Jan. 7, 2013, incident in a South Shore neighborhood during daylight hours.

A blue-light police camera shows Cedrick Chatman bolt out of a car and across a street with Officer Lou Toth on his heels. Chatman scoots through parked cars and toward an intersection. Less than 10 seconds pass from the time Chatman jumped out of the car to the fatal shots.

Officer Kevin Fry can be seen trailing behind Toth, aiming his gun at Chatman from a crosswalk and firing as the teen began rounding the corner in front of a bodega. One video from a camera that pans back and forth is grainy and it doesn't show Chatman fall; another is clearer and shows Chatman fall, but it is taken from farther away and doesn't show definitively if Chatman ever turned.

Immediately after Thursday's hearing, Chatman family attorney Brain Coffman was asked if a criminal case should be reopened based on the video and other evidence. He answered, "Absolutely." In a phone interview later, he said it was Cook County State's Attorney Anita Alvarez's call and that he hoped she would give the shooting "a second look."

But at a news conference on Thursday, Alvarez didn't seem inclined to do that.

When asked if she could reopen the Chatman case, she responded, "We looked at that case back in 2013 and determined that no criminal charges were warranted."

Fry, the only officer to shoot that day, said in a 2014 deposition that he opened fire with his .45 caliber semi-automatic pistol out of fear for his own life and his partner's after Chatman "makes a slight turn" holding an object.

"It was a small black object, which I believed to be a handgun," Fry said.

Investigators said later the object was an iPhone box. Coffman says the teen never turned toward the officers and posed no threat.

The Independent Police Review Authority, which investigates police shootings, cleared the officer who shot Chatman of any wrongdoing. However, court filings allege that the agency cleared the officer only after an investigator who opposed that finding, Lorenzo Davis, was fired. Davis has filed a separate lawsuit about his dismissal. IPRA has declined to comment on Davis' case because the litigation is ongoing.

In the Laquan McDonald case, the city fought the release of dashcam video for more than a year, making it public only after a state court ordered it to do so. The video and the delay in releasing it led to protests and calls for Mayor Rahm Emanuel to resign.

Chatman's family had asked that the video in his case be made public, arguing it would counter the city's narrative that Chatman posed a danger to police. City attorneys, until Wednesday, fought to keep it under seal on grounds its release could taint any jury pool should the civil case go to trial. They said in a Wednesday court filing that the city was dropping its opposition in an effort to be more transparent while it waits for a recently created special task force to review policies regarding the release of videos showing disputed police shootings.

Gettleman sharply criticized the city attorneys for suddenly changing their position on the video's release on policy grounds, not legal grounds, after spending weeks trying to prevent it.

"I went to a lot of trouble to decide this issue, and then I get this motion last night (Wednesday) saying that this is the Age of Enlightenment with the city and we're going to be transparent," Gettleman said. "I think it's irresponsible."

The Associated Press contributed to this report.