On March 22, Officer Jason Walters of the Portland (Ore.) Police Bureau was put in a position where no police officer wants to be. His back was literally up against a wall and an apparently demented man was approaching him with an edged weapon.

Thus began a nightmare for Walters who has been second-guessed in the press, accused of murder by groups of anarchists who have marched in Portland's oh so liberal streets, and even subjected to the absurdity of police "expert" the Rev. Jesse Jackson questioning Walters' tactics.

According to grand jury testimony by Walters and others, the March 22 incident went down like this.

At 3:05 p.m. 911 dispatchers received a call from the staff at Portland's Hoyt Arboretum saying that some homeless guy was drunk, bothering the park's visitors, and had threatened one woman. There was no mention of a knife.

Officer Walters, who knew the Arboretum and the local homeless well and even thought he might know the subject by name, volunteered to take the call. He also requested the assistance of the local detox unit.

The call wasn't a very high priority for anyone because there had been no mention of a weapon or actual violence. So Walters arrived 19 minutes later at 3:24. He was told that the subject was in the restroom. Walters knocked on the door and announced his presence. He expected a drunken homeless guy to come out and figured it would be pretty easy to persuade the guy to take a ride and sleep it off.

But the man who came out of the bathroom was not just drunk and homeless. He was by all accounts: crazed. He was holding a stainless-steel handled X-acto and he apparently had used it to cut on himself while in the men's restroom. Blood streaked his face and beard. And he moved "deliberately" toward Walters holding the X-acto.

Walters ordered the man to "drop it" while he backed up and considered his options. He knew he could only back up so far because of a rock and shrub wall that blocked his retreat. He wanted to use his OC spray, but the subject was too far away. He wanted to use his TASER, but the subject had a knife and Walters had no backup to provide lethal cover. "Drop it!" Walters yelled repeatedly. He couldn't think of the word "knife," the "it" that he wanted the subject to drop. (Walters later told the grand jury that he was "more scared" by this incident than anything he has faced in 13 years of police work.)

The subject kept moving forward, X-acto in hand. Walters backed up. The wall was getting closer. Worse, if he waited much longer, he knew that the angle of any defensive shots he might fire might send his rounds into the visitors center. "Drop it!"

In fear of his life, Walters opened fire. Two rounds struck the subject, but he kept coming. Walters fired two more. The subject - later identified as 58-year-old Jack Dale Collins - went down, mortally wounded.

A grand jury cleared Walters of any wrongdoing in the shooting. But before it returned that finding, this panel asked some of the dumbest questions in the history of jurisprudence. They wanted to know the usual: Why didn't Walters shoot the knife out of Collins' hand? Why didn't Walters shoot to maim? Why didn't the first two shots knock Collins down? Why would Walters be in fear for his life since he was wearing body armor? And my favorite of all time: An X-acto is just a small blade; could that really kill you?

That last point about the size of the knife was actually one of the primary arguments used by people who commented on stories in the Portland News and a primary contention of the city's liberal elite. Only someone who has never faced the real possibility of being slashed or stabbed would ask such a question. It's stupid beyond reason.

And that fortunately is the legal standard: reason. Graham v. Connor says officers can defend themselves with deadly force if they reasonably believe they are facing imminent death or serious bodily injury. That's the rules of engagement, and the Portland protesters, the anarchists, the news media, and even the Rev. Jesse Jackson can't change them. Thank God.