The first tragedy of the Trayvon Martin case is that it didn’t have to happen. George Zimmerman didn’t have to trail the teenager through the darkened streets of the gated Florida community, didn’t have to get out of his truck. He was told not to. But he did.

In the struggle that followed, the unarmed boy was shot and killed — an unarmed African-American teen, shot and killed by a Neighborhood Watch volunteer who found his presence “suspicious.”

It’s those details that caused a public outcry when police and prosecutors initially declined to charge Zimmerman with a crime.

Those same details hang over Saturday’s verdict.

The nation should respect the jury that found Zimmerman not guilty of second-degree murder. Defense attorneys argued that he fired in self-defense, and prosecutors couldn’t prove otherwise. Without enough evidence to challenge Zimmerman’s version of events, jurors had no choice but to acquit.

The jurors reached a unanimous verdict. The jurors did their job.

The same can’t be said of police and prosecutors in the aftermath of the shooting. It is their cavalier response — not the verdict — that compounds this tragedy.

The fact that the Zimmerman was eventually acquitted of the charge doesn’t validate the cursory dismissal by law enforcement back in February 2012. This case deserved to be examined thoroughly and adjudicated.

As the case moved to trial, many of those who led the campaign stressed that what they demanded was not an outcome, but a trial. But many now are bitterly disappointed at the result.

The trial was fair. The evidence came up short. The outrage was that there almost wasn’t a trial at all.