A COLD-HEARTED savage has murdered another Philadelphia police officer, and the city buckles, once again, in horror and disbelief.

It's an unrelenting plague, and its agent of death is - guns.

And the horrifying fact is that more guns than ever are being purchased in this country as uneasy people arm themselves in fear: Fear of a reversal of gun rights under President Obama. Fear for their safety in an economy that drives people to desperation.

Sure, I know: many are legal guns, bought by responsible gun owners who don't kill people, blah blah blah.

But my math is simple: The more guns in circulation, the more that find their way to the dregs of society who casually assassinate cops.

And there are more guns in circulation than ever.

Gregory Isabella, the owner of Firing Line Inc., a South Philadelphia firearms dealer, acknowledged having "a lot of new clients."

He was polite but terse, and unwilling to cooperate with a columnist whose work is "slanted" in favor of gun restrictions.

Mike Friedland was more willing to talk.

"There's definitely been a lot of extra sales," said Friedland, who owns French Creek Outfitters, near Phoenixville.

"We've seen spikes in sales before, what with the onset of the Brady Bill in the '90s, with the magazine [assault weapon] ban, with Clinton being elected," he said.

"But we've never seen spikes with this much fervor that have lasted as long. It's definitely unprecedented since I've been in business, 16 years."

This internal arms race began in November, with the election of Barack Obama and the ascension of Democrats to majority power in Washington.

"It's clear that gun owners and prospective gun owners are concerned about the Obama Administration and Congress," said Ted Novin, speaking for the National Shooting Sports Foundation, the trade association for the firearms and ammunition industry.

Friedland agreed.

"If you look at it practically, both houses of Congress are decidedly Democratic, and the fact that the president probably will get two or maybe three Supreme Court judges; that's what scares people most," he said.

"People are worried about the Second Amendment being in jeopardy."

Obama has verbally backed the Second Amendment as an individual right to bear arms, but also has endorsed the right of state and local governments to enact restrictions.

Friedland said that his fourth-quarter sales were up 15 percent and have shown no sign of abating.

Some critics think that gun sellers are exaggerating sales statistics as a marketing tool.

While there are no objective data on gun sales - neither the FBI nor ATF keep those statistics - the number of FBI background checks for firearms confirms the disturbing trend.

Last month, the FBI's National Instant Criminal Background Check System performed more than 1.2 million checks, compared to 942,000 in January of last year - an increase of 29 per cent.

December showed a slightly smaller increase over the previous year, and November - election month - triggered a record 1.5 million checks, 42 percent more than the previous November.

The number of new gun purchases is potentially far more than that: a customer could buy multiple weapons. And many of the guns sold at gun shows don't require background checks.

Friedland acknowledges that fear triggered by the economic downturn also could be contributing to ramped up gun sales.

A friend of mine reports that several associates of his - affluent and successful men - have bought guns for the first time in their lives to protect themselves from predators potentially unleashed by the disintegrating economy.

It's a tragic escalation of the arming of American society, with the inevitable spillover into the streets.

It puts the likes of Police Officer John Pawlowski at a tragic and fatal disadvantage.

And brings a city again and again, to tears. *

E-mail porterj@phillynews.com or call 215-854-5850. For recent columns: