Saturday's assassination of two police officers in New York City by a gunman with Georgia ties was terribly tragic, the kind of news that adds a pile of head-shaking sorrow to the holiday season. Not surprisingly, the murderer had a long record of mental illness and crime; a few hours before killing the police officers, he had also shot and tried to kill a former girlfriend in Baltimore.

To make matters worse, though, some people have seized on that tragedy and attempted to turn it to political advantage. For example, former New York Mayor Rudy Giuliani blamed the murders on "four months of propaganda, starting with the president, that everybody should hate the police." (Giuliani has yet to identify a single statement from President Obama that would even vaguely justify such a claim).

The president of the New York City police union was even more irresponsible, proclaiming that "there's blood on many hands tonight.... That blood on the hands starts on the steps of city hall in the office of the mayor." (While NYC Mayor Bill de Blasio has made repeated statements in support of his police department in the wake of the Eric Garner tragedy, he has also stressed the need to improve police-community relations and to adopt less aggressive police tactics.)

Bernie Kerik, the former New York City police commissioner and a one-time nominee for secretary of Homeland Security, used these actions of a single madman to warn about "a war on law and order" that has the potential to "cause damage far worse than any attack on our country, including that on 9/11/2001."  (Last year, Kerik was released from federal prison after being sentenced to four years after accepting bribes.) And U.S. Sen. Lindsey Graham tried to have it both ways, saying "the tone they're setting around the rhetoric regarding the cops incites crazy people, but I blame the shooter."

Frankly, such comments are reprehensible.

Calling for reform of police departments is not a call to go killing officers, and it's just plain asinine and disrespectful to claim otherwise. Furthermore, allowing protesters to protest is not the first step to declaring open season on law enforcement, and members of the public who raise legitimate questions about public agencies and public servants should not be equated to anarchists engaging in a war on law enforcement.

The hyperbolic response by NYC police union officials is particularly troubling since it comes after similar overheated responses by union officials in St. Louis over the Michael Brown case and in Cleveland over the shooting of a 12-year-old boy by a police officer.

Maybe it's just me, but when you're trying to rebut charges that police officers at times overreact to provocation and show poor judgment, that some officers believe themselves immune to civilian oversight, that they cover up for their own even in egregious cases and that they respond to criticism with excessive aggression, such statements don't help your cause much. To the contrary, they tend to undermine public confidence and confirm what critics say about you. And as much as we might like to argue that such spokesmen aren't representative of the police rank and file, it's difficult when they are in fact the chosen representatives of the police rank and file.

Finally, do the names Jerad and Amanda Miller ring a bell?

Last summer, inflamed by the anti-law-enforcement rhetoric surrounding the Cliven Bundy standoff, the Millers took it upon themselves to assassinate two Las Vegas police officers who were eating lunch at a pizza restaurant. They just walked in and blew the two officers away.

As you probably recall, the Bundy case involved scores of militia types in an armed, weeks-long confrontation with federal law enforcement. The threat of violence against law enforcement was quite explicit and palpable, yet Bundy still drew sympathy from a lot of quarters, including Texas Gov. Rick Perry, U.S. Sen. Rand Paul of Kentucky and U.S. Sen. Dean Heller of Nevada. Yet to my knowledge, no major political figures tried to blame Perry, Paul, Heller and others for the subsequent deaths of those two officers. They weren't accused of having police blood on their hands, or of fomenting war against those who wear the badge, nor should they have been. You could accuse them of exercising poor judgment in their statements about Bundy -- in my mind they certainly did so -- but they were not advocating or encouraging the murder of police officers.

That kind of accusation is extremely grave, and those who make it have forfeited all public respect.