As Wikipedia puts it, "McDonald, a 17-year-old black male armed with a 3-inch (76 mm) knife, was shot 16 times in 13 seconds by Chicago Police officer Jason Van Dyke." However, the strong impartiality bias of that platform makes it hard to suss out why this is a particularly salient news story, given that there are so many police shootings every year in the United States.
The (long suppressed) video evidence is particularly incriminating. It showed police officers who aggressively engaged their suspect, made no attempt to protect themselves, and one who fired a full 16-round magazine into McDonald without any immediate danger to himself or others.
There is substantial evidence of a concerted effort to cover up the incident.
- Immediately after the shooting, it was described in very similar terms as many other police-involved shootings were, including the falsehood that McDonald lunged at the officers.
- The existence of an incriminating video was only discovered after a police department whistle blower informed a reporter and attorney of its existence.
- A manager at a local restaurant has alleged that several police officers deleted additional video evidence immediately after the shooting.
- The video evidence was only released after a court order demanded it.
- Charges were only filed after the court order was handed down.
The case indicates that the Chicago Independent Police Review Authority and State's Attorneys office do not serve as an effective check against police power.
The case fits very well into the broader US narrative of "Black Lives Matter", where another Black person is killed by a police officer, and that death is long left unexamined and unpunished.
- Chicago leads the nation in raw number of police-related shootings, but this is its first major case captured on video after Ferguson.
Because one death is a tragedy but 1000 deaths are a statistic*. Civil rights movements which want to achieve a change often use appeals to emotion.
It is far more emotionally effective to single out isolated cases and use them as a stand-in for what is happening on a grander scale than just quoting statistics.
When one says "black men are x% more likely to be stopped by the police and y% more likely to be shot during it" it has not that much of an emotional impact on the listener. Even worse: It allows the listener to make up their own interpretation for the reasons for this statistic, and might interpret it in a way which reassures their own racist bias.
But when they tell tragic stories like those about the deaths of Michael Brown or Laquan McDonald, they humanize the victim as a stand-in for all the other victims. They give a face to the grander issue. This leaves a far greater emotional impact. It doesn't really matter for a civil rights movement which cases to single out as an emotional lever. Important is just that the cases represent the issue well.
And why does the media react to this so predictable? Because when thousands of protesters hold up pictures of a face and chant a name, people want to know why. So it's the job of the media to provide people with the background information and do research how justified this specific claim by a protest movement is. So the case gets far more media attention than similar cases.