PHILADELPHIA (CN) - A Walmart employee's hasty sale of handgun ammunition to a drunk underage customer led to a shooting rampage with three fatalities, the victims' families claim in court.

The families sued retail giant on New Year's Eve in the Philadelphia Court of Common Pleas, claiming an employee sold a box of ".38 caliber handgun ammunition" to 20-year-old Robert Jourdain in the wee hours of the morning following the Fourth of July.

An anonymous cashier in a Philadelphia-area Walmart Supercenter conducted the sale "without conduct[ing] any basic questioning" to see if Jourdain was at least 21 years old "as required by law," according to the lawsuit.

Not only did Walmart staff fail to card Jourdain, the lawsuit says, they were similarly undeterred by his inebriated condition. The plaintiffs claim Jourdain was "mentally incapacitated by drugs and/or alcohol" when he walked into Walmart, having spent "at least four hours" in a bar prior to making his purchase - another red flag that should have led the store's staff to deny him service, the families say.

Within an hour of the transaction, the family says the bullets became evidence in an crime spree that took the lives of three people on the streets of nearby Easton and Allentown, Pennsylvania, with each one dying of "multiple gunshot wounds."

The deaths added to a growing list of such fatalities in 2015, a year so marred with gun violence that it sparked national debates and on Tuesday inspired President Barack Obama to issue an executive order expanding the background check process for gun buyers and tightening restrictions for firearm dealers.

The murders were committed by Jourdain's cousin, Todd West, who reportedly waited in a car in the Wal-Mart parking lot while the ammo was purchased.

Neither Jourdain nor West are parties to the complaint.

One victim, 22-year-old Kory Ketrow, was shot multiple times in the chest "within footsteps of his home" just minutes after the bullets Jourdain bought had been loaded into his gun. Though "alive, conscious and gasping for air" when first responders arrived on the scene, Ketrow succumbed to his injuries while being treated at the hospital, the complaint says.

Just 20 minutes later, Francine Ramos and Trevor Gray were slain in a drive-by shooting, their parents say in the lawsuit.

Ramos was found bleeding from the head in the driver's seat of her car and Gray was slumped against the exterior of a nearby car, where he'd "attempt[ed] to run and take cover" after the gunman opened fire, the parents say in their complaint.

West reportedly confessed to the crimes the next morning, after police found the vehicle used in the shooting. The car was loaded with evidence, which included "a Walmart bag with the partially empty box of .38 caliber Winchester ammunition sold by defendants earlier that morning, a fully loaded .38 caliber Smith & Wesson revolver, and 12 discharged cartridge casings" from the box of ammo, the lawsuit says.

Autopsy reports showed all three victims had .38 caliber bullets lodged in their bodies, the lawsuit says.

Their surviving family members are seeking unspecified punitive and compensatory damages from Walmart for wrongful death and negligence.

The families accuse Walmart, general manager Nicole Everett, sporting goods manager Addiel Javier and a cashier identified in the complaint as John Doe of violating gun laws by selling ammunition to a customer who did not meet the defined "legal minimum age" to buy it, and by failing to employ "any precautions, investigation or basic questioning to define his age."

"[The defendants] knew or should have known that Mr. Jourdain intended or was likely to use the bullets to kill other persons or to create an unreasonable risk of harm to others and the general public," the lawsuit says.

Walmart national media relations director Randy Hargrove said in a telephone interview that the transaction unfolded differently than the lawsuit claims, maintaining that store registers have a prompt requiring cashiers to verify a customer's age in order to conduct a handgun-related sale.

Hargrove said the box of .38 caliber Winchester ammunition Jourdain purchased could have been used in either a rifle or a handgun. Jourdain told the cashier the bullets were for use in a rifle - for which the legal purchase age is 18, Hargrove said.

The purchase was therefore permissible and cashier did not violate any laws in making the sale, nor did Jourdain display any signs of intoxication while he was in the store, he said.

"We will review the complaint and intend to defend the company against this litigation," Hargrove wrote in a follow-up e-mail.

But the families' 51-page lawsuit refers to the bullets as "handgun ammunition" in every mention, making no reference that the ammunition can also be used in rifles.

The firearms information section of the Pennsylvania State Police's website states that an individual must be 21 to apply for a license to carry firearms, but contains an exception for a "sportsman's firearm permit" used for hunting and fishing, which can be possessed by an 18-year-old. The section does not mention rifles or make distinctions between different types of ammunition.

The estates of all three deceased plaintiffs are represented in the suit by their parents. Their attorney is Matthew Casey of the Philadelphia firm Ross Feller Casey.

This story was originally published by Courthouse News.

Also on HuffPost:

PHOTO GALLERY Pivotal Moments In The U.S. Gun Control Debate