400 Days? Really, Alvarez? Really, McCarthy? Really, Rahm?

The release of the dash-cam video showing 17-year-old Laquan McDonald being shot to death by Chicago Police officer Jason Van Dyke will help members of the public answer some questions about the incident. Is it as bad as those who have seen it say it is? Does the viewer see any mitigating, justifying factors in the images?

But it will not answer what ought to be the central question here: What took so long for officials to act?

Tuesday marked 400 days since the shooting took place on Oct. 20, 2014.

Yes, there are overlapping jurisdictional issues -- the Independent Police Review Authority, the Cook County state's attorney's office and the FBI all were involved -- but come on. There was no mystery here, no dead-end leads to pursue, no ambiguity about who fired the shots. Just a dead kid with 16 bullet holes in him, a limited number of witnesses and a purportedly damning video.

Day by day, week by week, month by month, what happened here? Who was pursuing justice and the truth and what were they doing? Who were they talking to? With whom were they meeting? What were they trying to figure out for 400 days?

We have a pretty good idea what prompted or forced them to act Tuesday, when Van Dyke was charged with first-degree murder -- a judge's order last week that the video be released.

But we still have no good explanation why it took so long. What piece of information, what testimony, what conclusion from which governmental body were they waiting for? Or, as we are left to conclude, were they simply biding their time, hoping the video would never be released and that this incident would simply fade from memory?

Cook County State's Attorney Anita Alvarez has some serious, detailed explaining to do. So does Chicago Police Superintendent Garry McCarthy and, by extension, Mayor Rahm Emanuel.

We can't expect every police officer always to behave well, particularly when emotions are running high.

But we can and should expect supervisers, investigators and prosecutors to respond quickly and objectively when cops go bad, to lead the legal and public relations efforts that, in the long run, hopefully, will minimize instances of police misconduct.

The delay here -- what looks like delaying tactics -- will understandably fuel the outrage, as it has fueled the outrage in the case of Chicago Police Detective Dante Servin. It was 1,351 days between March 12, 2012, when Servin, off duty, shot and killed 22-year-old bystander Rekia Boyd during an altercation over loud music, and Monday, when McCarthy finally announced he would move to fire Servin.

And other questions about the McDonald case remain.

Why, for instance, have we still heard so little about action against the officers involved in the deletion of 86 minutes of video from security cameras at a Burger King restaurant near the scene of the shooting?

The deleted files cover the time from 37 minutes before McDonald was killed to 49 minutes after he was killed. Burger King officials say a group of officers came into the restaurant after the shooting and were given access to the surveillance equipment. It wasn't until the next day that the restaurant discovered that the video was missing.

Will it take another 400 days until we find answers to that question?