Civil unrest at home and overseas mixed with seasonal stress could create a nasty holiday season.
Joey Walker, a retired Reno, Nevada, police lieutenant who teaches self-defense, told Fox News that holiday fun-seekers "need to keep their head on a swivel" and be mindful of potentially hostile crowds and protests.
"Things can go from good to bad almost without warning," he said. "Based on the fact that we have a lot more active shooting cases these days, I would be really surprised if we didn't see several of those before the end of the year occurring, especially around the shopping malls."
Tensions are unsually high as it is, but the holidays tend to make people feel more stressed and depressed.
"People are irritated for one reason or another," Walker told Fox. "Whether you like this side or that side, whether it's a political situation with a religious ideology, you're going to have individuals that are angry enough to show up and want to hurt people."
While out shopping, the holiday spirit can make some people blissfully unaware, which can put them in a precarious position if someone with heightened emotions has a breakdown.
"Shoppers who are actually in the holiday spirit are going to be relaxed, so their guard may be significantly down. They're thinking about the presents that they're going to be getting for their loved ones, their friends," Walker told Fox. "We've got individuals who want to prey upon those individuals, who want to target them."
That's why it is especially important to pay attention to your surroundings, Walker added, not just this holiday season but any time you are out in public.