This is an archived article that was published on sltrib.com in 2016, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Smyrna, Ga. • Adventure Outdoors is an 80,000-square-foot store with walls lined with long guns, cases packed with handguns and aisles jammed with all the accessories an avid outdoorsman would need: coolers, clothing, ammo. At the customer service counter is a government-issued poster that warns: "Don't lie for the other guy."

Store founder Jay Wallace said his staff is diligent about making sure buyers are legitimate and not fronting for someone who is legally prohibited from buying a gun. But once a sale goes through, he said, it's out of his hands.

"A firearm takes on a life of its own after it leaves. It can be bought and sold many times over," Wallace said.

The flow of guns from one person to another, and from states with loose gun laws to those with strict ones, has long flummoxed law enforcement and gun-control advocates and is emerging again as a hot topic.

Democratic presidential candidate Hillary Clinton singled out rival Bernie Sanders' home state of Vermont, which has few gun restrictions, for supplying a disproportionate share of firearms used in crimes in New York. (In reality, more guns flow in from states to the South.)

While the vast majority of guns used in crimes were originally sold legally, what happens to such weapons after their initial sale is difficult to track and even harder to prevent, because most criminals get their guns from friends, family or on the street.

The government has two snapshots of a gun: where it was purchased and where it was recovered, an incomplete picture because not every gun recovered by police is traced.