. >> reporter: this firearm instruction class in the miami area is led by gun store owner, david kowalski. >> it's one of those things that you don't want to need and not have >> how many of you never thought you would ever personally own or use a gun >> reporter: the class featuring a profile of people you might not expect to find grandmothers and guns, not always an obvious pairing. >> i'm like having an out-of-body experience sitting here >> reporter: but as israel's campaign in gaza grows more deadly, so too does the fear of backlash >> every single country, every single town is demonstrating against our people we feel terrified. >> reporter: kowalski says his classes have gone from one or two a week to one or two a day. >> after the hamas invasion, did you see an immediate change in your business? >> yes, absolutely there was definitely an uptick in jewish americans wanting to learn how to protect themselves and their families. >> reporter: for many of the firearm newcomers we met, there are still reservations >> scary >> very good >> it's scary. >> reporter: but for others, there is

it's terrifying. >> reporter: kowalski says his classes have gone from one or two a week to one or two hamas invasion, did you see an immediate change in your business? >> yes, absolutely. there was definitely an uptick in jewish americans wanting to learn how to protect themselves and their family. >> reporter: for many of the newcomers we met, there are still reservations. >> scary. >> very good. >> it's scary. >> reporter: but for others, there is no longer a choice. >> people who can't respect human life, how can you think that they're going to care about force? >> reporter: the concern that's growing in jewish communities all over the country. sam brock, nbc news, south florida. >>> and next, remembering a legendary college basketball coach, the fiery bobby knight. dr. garcia? crest reality checkup. that grimy film on your teeth? it's actually the buildup of plaque bacteria which can cause cavities in months. and your toothpaste just isn't cutting it. most toothpastes quit working in minutes. but the antibacterial fluoride in crest pro-health protects for up to 12 hours. so i can

>>agent kowalski believes that aryana's move to italy was a calculated maneuver.t, having those twins was part of the ploy. >> she had children there. i believe it was a means to justify her citizenship in order to stay there. >> it appeared as though aurea had outsmarted the federal authorities and was perhaps even thumbing her nose at adam 's family and friends. >> i can honestly tell you she is one of the very few people i ran into, almost 27 years in the fbi, that we would say is really evil and conniving, calculating. >> but for all of her alleged planning to allude the fbi, there was something or rather, someone aria had overlooked. abe anhang. and here's an older gentlemen who is smaller in stature but what was your impression of him? >> adam's dad was just such a brave man. >> it may be a small man but he is a, powerful smart man and able to modulate his emotions, strategic. >> do you think aurea even knew what was coming her way? >> absolutely not. >> abe was not a lull to give up his pursue. >> she couldn't run off to europe and start a new life all over

. >> reporter: at a firearm instruction class in south florida led by david kowalski, it's a pro-feelout-of-body experience sitting here. >> reporter: grandmothers and guns, not necessarily an obvious pairing. >> don't want to be a sitting duck. somebody comes to hurt me or my family. >> reporter: dave sells firearms and offers classes and says his phone has been ringing off the hook. after the hamas invasion did you see an immediate change in business? >> yes, absolutely. there was definitely an uptick in jewish americans who want to protect themselves and their families. >> reporter: his classes went from one or two a week to one or two a day. as for the current reality -- how many of you never thought you would ever personally own or use a gun? it's not something many in this group have grappled with until now, and it's happening coast to coast. >> so we can hardly keep our head above water. >> reporter: this rabbi runs the only nonprofit on the west coast doing community-wide education, firearm training, and security in los angeles where hundreds of people are showing up at meetin