Halloween is one of the most dangerous holidays of the year for kids. It has more child pedestrian deaths than any other day of the year. Kids also get tangled in their costumes and injure themselves. But there's something that isn't a real problem: strangers giving trick-or-treaters apples with razor blades, poisoned candy or drugs.

For decades, Halloween-safety public service announcements and police officers have advised parents to inspect their children's candy before letting them eat it. Generations of kids have been told bad people want to hurt them by tampering with their Halloween candy.

"This is absolutely a legend," said Joel Best, a professor of sociology and criminal justice at the University of Delaware, who has studied contaminated candy since the 1980s. "It's not a particularly great legend ... but it lives on."

When Best was in graduate school in the late 1960s, the fear of tainted candy was already a widespread concern. There were also moments when that fear spiked, like after the Tylenol killings in 1982. Seven people died after being poisoned by painkillers laced with cyanide. This led to speculation that Halloween candy would be dangerous that year. But there was no wave of Halloween poisonings.

The topic would come up with Best's students and friends. They were outraged that he didn't think the candy danger was real. So he started digging through newspapers, searching for cases of it happening.

"I have data going back to 1958, and I have yet to find a report of a child that's been killed or seriously hurt by a contaminated treat picked up in the course of trick-or-treating," said Best.

Best says he found one case of a man in Texas murdering his own son with poisoned candy. He thought it would be the perfect crime, because he thought children constantly got poisoned like that.

Then there are cases of Halloween deaths that were initially attributed to what Best calls "Halloween sadism." But he says none of them ended up being the real deal.

One of those cases was a girl in Los Angeles who died from a congenital heart problem. "The media originally reported it is probably candy contamination, and the autopsy concluded it was a death by natural causes. There have been a couple other cases like that," said Best.

If you see videos online of people claiming to have found a needle in a candy bar, it's best to be skeptical. It's likely to be a hoax.

"It's a very simple matter for a child to take a pin, stick it in a candy bar, run in and say, 'Mom, look what I found,' and be rewarded with the concerned attention of adults," Best said. "If people press these folks, they'll almost always say, 'Yeah, that was a joke.'"

Best has been dispelling this myth for years and telling people they shouldn't worry about people tampering with treats. But even with no evidence of this happening, the urban legend still persists every Halloween.

"We've stopped believing in ghosts and goblins, but we believe in criminals," said Best. "Ghosts and goblins are just kind of silly. But having a criminal, having Michael Myers running around your town, that's a scary possibility."

And over the last 50 years, people have become increasingly concerned about danger to children.

"We live in a world that we can't control. All kinds of terrible things ... could happen, and it could all come tumbling down. How can we control it? One of the ways that we do this is we become very concerned about the safety of children," said Best.

Best never inspected his children's Halloween candy and doesn't think it's necessary for parents to do so. With no evidence of any injuries or deaths from candy tampering, that is one less frightening thing to worry about on Halloween.

Barry Gordemer edited the audio story, and Treye Green edited the digital story.