Luke Goodman, 22, shot and killed himself after eating a large amount of pot edibles, authorities say. (Courtesy of Kim Goodman)

The last time Kim Goodman saw her son alive, it was at a bus stop in central Colorado, and he flashed that toothy smile that she so loved about him.

The Oklahoma family was on a vacation in the Rockies. Her son, Luke, was about to make off on his own to go snowboarding with some of his cousins. She recalls a contented feeling as she saw him leave. They had just had a really long talk the night before, and he looked so full of life — tan, fit, fresh out of Oral Roberts University. Ready for anything.

Days later, he would be dead. Luke Goodman, 22, shot himself once while alone inside a bedroom at a ski resort in Keystone, Colo.

That was Tuesday. And in the days since, the Tulsa mother has struggled to reconcile the vibrancy with which her son lived and the violence of his death. The pieces don’t fit: He was so happy when he left her. He loved athletics and was out snowboarding. He was with his cousins, people who loved him more than anything. How could this have happened?

Then her nephew, Christopher Fouler, who was with her son that day, told her. Things began to fall into place. She knew her son had smoked pot before. But he had never had any marijuana edibles, as far as she knew. On the day of the shooting, he had taken five pieces of marijuana candy — four peach tarts and one red velvet. “We are absolutely convinced it was the edibles that led to his death,” Kim Goodman told The Washington Post on Thursday.

The story of Luke Goodman feeds into a larger debate over the ramifications of legalized marijuana and the diversification of marijuana products. One of the most contentious aspects of that debate involves edibles — and their safety. If Goodman’s suicide was related to marijuana intoxication, it won’t be the first.

In March of last year, when a college student fell from a hotel balcony, the Denver coroner’s office reportedly listed marijuana intoxication as a contributing factor. Then there’s the case against a Denver man who authorities say ate a marijuana candy and then shot his wife dead.

The thing is, medical experts wrote in the New England Journal of Medicine, marijuana edibles are supremely popular. And companies are meeting the demand by rolling out a dizzying variety of pot snacks like Keef Kat and Munchy Way. But critics say regulation is lax.

“Though the ingenuity and swiftness with which manufactures have formulated the new edibles have been surprising, the general problem was predictable,” wrote doctors Robert MacCoun and Michelle Mello. “As legalization of marijuana spreads, new adopters should ensure that their regulatory scheme for marijuana edibles is fully baked.”

Edibles present unusual issues. “What we’re seeing with edibles is that the effect is delayed for approximately 30 minutes, depending on the person,”  Al Bronstein, a physician and medical director of the Rocky Mountain Poison and Drug Center, recently told ABC News.  “People get impatient for the effect and will take more, and then the symptoms are more pronounced than what they were expecting.”

It’s too early to conclude pot edibles contributed to any of these deaths. Suicides are often a fueled by a combination of factors, with no single cause leading to tragedy. But to Kim Goodman, that wasn’t the case with her son. She’s convinced his curiosity about pot edibles killed him.

When she left her son that day at the bus station, she knew he had his gun with him. The Goodmans are a gun family. As Goodman was growing up, he watched his father bring a gun on vacation trips to lend the family a sense of security. So when Goodman learned he would be taking a leg of the family’s Colorado trip by himself, he bought a 9mm and brought it with him.

Soon Goodman met up with his cousins. He said he had noticed a pot dispensary near the bus station, and his mom said the young men went back there and bought a bag of pot candies. “He wasn’t familiar with them,” she told The Post. “So he ate one, but 15 or 20 or 30 minutes later, he said, ‘I’m not feeling a thing.’ So they decided to take another one, then another one, then another one. And ultimately, he ended up taking five edibles.”

Goodman seemed fine for a long time. A pair of friends of his had just gotten engaged. Goodman was thrilled, and his Facebook page shows he called them to offer congratulations.

But inside the Keystone resort, it was getting late, and things were getting out of control. Goodman and his cousin, Christopher Fouler, got into an “intense debate” about religion and politics, police records reported by 9News said. Fouler said Goodman started “going overboard,” so he said maybe they should hit the hot tub.

“My nephew and his girlfriend said, ‘Hey, Luke, let’s go down to the hot tub,'” Kim Goodman said. “And he said, ‘No, I’m going to stay up here.’ So my nephew walked down to the hot tub and, two minutes later, a gunshot goes off. It was from the bedroom. Where my son was.”

Her nephew found her son there. He was wearing snowboard boots, ski pants and a ski jacket.