The two handguns and two rifles used by ISIS-inspired Islamic terrorists to kill 14 and wound 21 at a Christmas party earlier this week in San Berndardino, CA, were purchased legally four years ago under some of the strictest gun control laws in the United States.

The four weapons used in the San Bernardino mass shooting were purchased more than three years ago and one or more of them were purchased at Turner’s Outdoorsman, a Southern California-based retail chain, according to a law-enforcement official.

The official declined to give details on which of the weapons were purchased at Turner’s or which branch made the sale.

Bill Ortiz, vice president of compliance for Turner’s, said the store cooperates fully when law-enforcement requests information pertaining to purchases. Mr. Ortiz would neither confirm nor deny whether the chain had been contacted by authorities regarding the weapons used in the attack, as per the company’s corporate policy.

The weapons were illegal under California law because they were modified and violated the state’s ban on assault weapons, the Bureau of Alcohol, Tobacco, Firearms and Explosives said on Thursday.

Syed Rizwan Farook and Tashfeen Malik, the suspects in the Wednesday shooting that left 14 people dead and 21 wounded, were armed with four guns. They carried two .223-caliber semiautomatic weapons and two 9mm semiautomatic pistols, according to San Bernardino Police Chief Jarrod Burguan.

The two semiautomatic rifles were versions of the popular AR-15 model, according to San Bernardino officials. One was made by DPMS Inc., and the other by Smith & Wesson.

While they were originally sold legally, with magazine locking devices commonly known as bullet buttons, the rifles were subsequently altered in different ways to enhance them, according to Meredith Davis, a special agent with the ATF.

The Smith & Wesson rifle was changed in an attempt to enable it to fire in fully automatic mode, while the DPMS weapon was modified to use a large-capacity magazine, she said.

Those alterations made the weapons unlawful under California’s ban on assault weapons, which bans guns with magazines that can detach for quick reloading.

In plain English, Farook walked right through California’s paper laws on what constitutes a “legal gun,” just as he walked through laws against murder.

The 9mm Llama and Springfield Armory XD pistols were utterly unremarkable in every way, though Farook apparently equipped the XD with an aftermarket grip sleeve for comfort.

The two AR-15 carbines appear to have been purchased legally, but not transferred through an FFL.

They were both semi-automatic (one shot per trigger pull), and Farook discovered something that the ATF could have told him in advance; it’s very difficult to convert an AR-15 to automatic fire without significant knowledge and equipment. He attempted to convert the M&P15 to fire fully-automatic, and botched the job. He’s lucky it still worked.

The rifles were later equipped with cheap aftermarket “grip pod” type foregrips, single-point slings, and red-dot optics, none of which made the rifles “more powerful” as claimed in an earlier Wall Street Journal report.

The San Bernardino terrorist attacks showed the futility of California’s strict gun laws, the inability of citizens to defend themselves under the state’s restrictive “may issue” concealed carry permitting scheme, and the failure of policies designating public buildings like the Inland Regional Center as “gun free zones.”