Perhaps the most disturbing image from the Laquan McDonald dashcam video released Tuesday is the wisps of smoke.
They waft off the 17-year-old's body while he is crumpled in a heap after being shot multiples times, allegedly by indicted Chicago Police Officer Jason Van Dyke.
Whatever danger Van Dyke perceived when he fired the initial shots into McDonald, who was on drugs and had been behaving erratically, it's impossible to see what damage he could have done while on the ground.
The smoke that drifted in the October air came from a total of 16 bullets.
Hundreds of angry protesters chanted the number Tuesday night as they marched the streets of Chicago and issued calls for Police Chief Garry McCarthy's head. More protests are planned for the Thanksgiving weekend.
The topic of white police officers killing young black men has gripped the nation since last August, when Darren Wilson fatally shot Mike Brown in Ferguson.
The issue is not a new one.
In 2007 I investigated fatal police shootings in Chicago and the nation for The Chicago Reporter.
During the project we submitted multiple requests under Illinois' Freedom of Information Act asking for the reports the police compiled in their post-shooting procedure.
The process was shrouded in secrecy.
We fought for the information for more than a year, eventually receiving only a handful of heavily redacted reports.
Given the department's intransigence, we built a database of eight years of fatal shootings from area news sources like the Tribune and Sun-Times.
Along with a team of dedicated interns, we dug into hundreds, if not thousands, of court cases to determine if officers who had been the subject of wrongful death suits had been sued before.
We also looked at the department's internal discipline system.
The results were striking.
In Chicago and the nation's 10 largest cities, the victims were disproportionately black.
Close to half of Chicago officers sued in wrongful death suits had been sued before, and more than half of that group had been sued multiple times.
And of the more than six dozen fatal incidents that had taken place during the eight years, only one officer had faced internal discipline. That officer was later promoted by Phil Cline, the man who was superintendent at the time we did the project.
For the national part of the investigation we used data from the FBI's Supplementary Homicide Report. The compilation of data submitted by individual police agencies, it has widely been criticized as inaccurate.
At the same time, Craig Futterman of the University of Chicago Law School and Jamie Kalven of the Invisible Institute were fighting to have records of alleged misconduct by police officers released to the public.
During the course of our investigation several young black men were shot and killed by the police.
Aaron Harrison, an 18-year-old African-American, was one of them.
His death led to protests but did not cause real political harm to then-Mayor Richard Daley, who had rolled to his sixth consecutive electoral victory earlier that year.
Daley created the Independent Police Review Authority in an effort, he said, to boost transparency and heighten accountability.
As horrifying as McDonald's death is, faint signs of progress are discernible in the circumstances surrounding the fact, release of and fallout from the video.
The video in which Van Dyke is alleged to have shot Laquan McDonald 16 times would not have existed eight years ago because police did not have those cameras on their dashboards.
The video's entering the public domain was the result of two Freedom of Information Act requests that Cook County Judge Frank Valderamma ordered the police department to honor.
The first-degree murder charge filed by Cook County State's Attorney Anita Alvarez was the first such charge in 35 years, sources said.
News reports this morning pointed out that Van Dyke has been named in 20 misconduct complaints. Four are open and his actions have been deemed justified in the rest. The availability of this information is from a public records request in the Tribune and is part a result of Futterman and Kalven's victory in court in having those types of records introduced to the public.
British newspaper The Guardian has started an innovative project called The Counted in which the paper uses their reporting and verified crowdsourced information to get a more accurate count in real time of the number and demographics of people killed by police in the United States.
It's important not to overstate the good news.
As friend and former colleague Angela Caputo wrote in early 2014, the victims continue to be disproportionately African-American in Chicago. The IPRA's record of officer accountability remains spotty at best.
It would be naïve to think that the changes that have occurred have come voluntarily from the police or that the timing of Alvarez's indictment was not prompted by the release of the video which has been available for more than a year.
The criticism of Van Dyke's conduct by Mayor Rahm Emanuel and yesterday's firing by McCarthy of Dante Servin, the officer who killed Rekia Boyd after shooting over his shoulder, seem calculated and callous at best.
These slivers of change amidst substantial continuity illustrate the ongoing need to fight for a more just and open city whose streets far too often have been soaked with the blood of young black men, including one whose life literally went up in puffs of smoke.