CHICAGO (AP) — Janet Lindsey Ferguson has carried a poster bearing a photograph of her teenage son, Rickey Childs, ever since he was shot and killed by a Chicago police officer in 2012. She’s handed out fliers to drum up interest in his death and maybe get someone to believe that the gun police said Childs fired at officers was planted near his body after he was shot in the head.

Now, after the release of the video of a Chicago officer firing 16 bullets into the body of another black teen, Laquan McDonald, she has hope that McDonald’s death — and the murder charge against the white officer, the first in decades to be charged with a crime for an on-duty shooting — will prompt someone to take another look at her son’s case.

“I know I can’t get closure but maybe I can stop crying every night, get a little rest,” she said.

Ferguson isn’t alone. Several relatives of people who’ve died in police shootings in Chicago see the McDonald case as both a tragedy and their best chance at justice. They’re pressuring the city’s beleaguered Independent Police Review Authority, or IPRA, to reopen inquiries into their family members’ deaths, and see the federal Department of Justice’s investigation of the Police Department as a chance — maybe the last one they will get — to be heard.

Dana Cross’ family received a $2 million lawsuit settlement from the city after IPRA ruled the 2011 shooting death of her son, Calvin Cross, who was black, was justified. While the money is going toward Calvin’s small child, she remains dissatisfied that none of the officers paid with their jobs for what they did.

“I have been trying to figure out what to do, who can I talk to and how I can get my story heard but I was just tired,” she said. “Then when the Laquan McDonald case came up, it gave me the push I needed.”

Since the McDonald video and others, including one of a police officer fatally shooting a man in the back, have been released, authorities are getting calls to investigate cases that have been closed for years or barely noted by anyone but the families of those who died. IPRA has already opened one investigation after a video showed a man being dragged by police from a jail cell and the agency’s new head has asked the city’s inspector general to again look at the McDonald case.

Plus, there are at least two dozen disputed police-shooting cases that have triggered lawsuits and have received some media attention and likely dozens more where lawsuits are contemplated or filed with little notice.

“That video showed what we are going through out here, what these police officers are covering up,” said Gloria Pinex, whose son, Darius, was killed by Chicago police in 2011.

The attention and requests have put the Police Department, Mayor Rahm Emanuel and prosecutors under intense pressure and has police officers wondering if they might soon be called to answer questions about shootings that were investigated and deemed justified.

Dean Angelo, president of the police officer’s union, worries that officers could lose their jobs and even their freedom.

“They might look for grounds to bring the officers up on charges,” he said.

On one recent night, relatives of those killed by police and others rallied downtown before marching up to the U.S. Attorney’s Office with a written demand for investigations into several shootings by police and alleged police torture cases — handing over pretty much the same document they said the same office ignored last year.

Dana Cross hopes the pressure will add up to someone answering for her son’s death. She already has some satisfaction: Earlier this year, Chicago Public Radio reported that tests showed the gun police said Cross fired at them was inoperable, that IPRA had determined the gun had not been fired and that there was no gun residue on Cross’ hands.

“Those officers are working now and they shouldn’t be,” she said. Cross’ attorney, Tony Thedford, said his client is hopeful for justice but would be a “fool” to be optimistic.

Pinex has more cause for optimism than most. A federal jury ruled against her in a lawsuit earlier this year, but new evidence came out — some in the middle of the trial — that contradicts an officer’s statements that he stopped Darius Pinex’s car because it matched the description of one that police were looking for in an earlier shooting.

It turns out, according to Pinex family attorney Steven Greenberg, that the call was not broadcast on the officer’s radio. Greenberg said he’s hopeful that a judge will order a new trial in the case.

But Pinex isn’t sure the results will be different.

“The last time (the jurors) knew the witnesses were lying on the witness stand and them jurors still sided with them (the police),” she said.

And the sight of Jason Van Dyke, the officer indicted Tuesday on six counts of first-degree murder and one count of official misconduct in the McDonald shooting, walking out of jail after posting bond was, for her, another reminder that the legal system is rigged in favor of police.

“I wouldn’t have got bail,” she said.