JACKSON, Miss. – If a store sells ammunition to an underage person who uses the bullets to kill someone, is the retailer responsible?

Not necessarily, according to the Mississippi Supreme Court. The court ruled 5-4 this week in favor of Walmart.

The lawsuit was filed by the relatives of Robert Williams, who was shot and killed by his girlfriend’s son in 2006. The son, Xavier Zurndell Moore, was 20 years old at the time, and shot Williams with a pistol cartridge purchased at the Walmart.

Federal law requires that a person be 21 to buy pistol ammunition. The lawsuit claimed that a store employee allowed Moore to obtain the ammunition through a straw purchase, meaning the worker sold it to Moore’s 21-year-old friend, while knowing Moore would be the recipient.

The next day, Moore went out with his girlfriend. By early morning, they were in his room with the door locked. Williams banged on the door and demanded a fan Moore had borrowed. Moore said he shot through the door in an attempt to scare him, but accidentally shot him in the head.