We ask an awful lot of our law-enforcement officers. That was the moral of two very different stories today involving big city police officers and their interactions with 17-year-old suspects This morning on the Vine Street Expressway, Philadelphia survivied a violent, chaotic scene with something that's in short supply these days -- some good fortune -- in a case that put in exclamation point on how officers so often risk their life to protect the public from violent, reckless bad actors.

We were lucky that no kids were on the school bus that was rammed by an out-of-control 17-year-old brandishing a gun and then shooting at a state trooper, first in traffic and and then again after he was stopped. And Philadelphia is even more lucky that the shoulder wound suffered by State Trooper Patrick Casey was not life-threatening, and that he should be home to spend Thanksgiving with his family. Trooper Casey had to make split-second life-and-death decisions. And like most skilled officers in most tough situations, he chose well. And the truth is, despite the uptick in protests over policing in the last 15 months, most folks get this. Because they get this benefit of a doubt, it's rare when an officer is charged criminally for the shooting or abuse of a suspect, and rarer still when a cop is convicted of a serious crime.

As I said, however, much is asked of police officers. We also ask law enforcement to be honest and transparent, because at the end of the day the police still work to serve the public. And we can't have them lying to their bosses...us. And yet in Chicago, in another case involving a 17-year-old criminal suspect, the police not only lied but then worked overtime to hide their actions from the people of America's third-largest city. It's possible to acknowledge the grave risks that law-enforcement officers take and to still ask them to be truthful. In fact, it's imperative that citizens demand this.

Here is what Chicago police initially said about the killing of 17-year-old Laquan McDonald -- who was walking erratically down the middle of the street and carrying a folding knife -- in October of last year:

A squad car arrived on the scene, and officers spotted the teen -- later identified as Laquan McDonald -- standing next to a car with a knife in his hand, Camden said. The teen began walking toward Pulaski Road and ignored the officers' requests to drop the knife, Camden said.

"He's got a 100-yard stare. He's staring blankly," Camden said of the teen. "[He] walked up to a car and stabbed the tire of the car and kept walking."

Officers remained in their car and followed McDonald as he walked south on Pulaski Road. More officers arrived and police tried to box the teen in with two squad cars, Camden said. McDonald punctured one of the squad car's front passenger-side tires and damaged the front windshield, police and Camden said.

Officers got out of their car and began approaching McDonald, again telling him to drop the knife, Camden said. The boy allegedly lunged at police, and one of the officers opened fire.

For more than a year, Chicago cops kept the dash-cam video that showed the entire shooting under wraps as if it were the briefcase holding the nuclear codes. Today -- with authorities forced finally to release the video by a court order -- we can see why they tried to cover up the evidence, because what happened was nothing like what police told the public. Watch the video at the bottom of this post. There was no lunge. There was no slashed tire. Just a cop firing 16 shots at a suspect with a knife, just six seconds after jumping out of his cruiser.

In the Laquan McDonald case, there is, belatedly, some justice. The officer has been indicted for first-degree murder, and the family has been paid $5 million, not that any amount can compensate for the loss of the son. Still, there are so many questions.

Is it really not possible to perform CPR or offer any kind of medical assistance to a wounded suspect, especially when, as the video shows, the knife was immediately kicked away from the dying suspect. I understand that there are safety protocols, but isn't there also common sense...and human compassion? We've seen the same unfathomable lack of response in North Charleston, S.C., and elsewhere.

More importantly, is it really not possible to be brave and yet honest at the same time? Instead, we repeatedly see law enforcement, mayors and other top officials working to hide basic public information -- whether it's dash-cam videos or even the names of the officers who are involved -- from the actual public. That's the hallmark of a police state, not a democracy.

The things we saw today are not a contradiction, not at all. In Philly, we saw a reminder of the best that law enforcement has to offer, but in Chicago, we saw worst possible abuse of the public's trust, a bald-faced lie. We can always do better. We must.