>> reporter: 25-year-old trystan scott wicks was arrested in a parking lot after his ex-girlfriend alertede that he had sent her several texts, allegedly threatening a mass shooting. experts say it shows the power of people paying attention. >> we need to have a reporting system and know that it's okay and actually it's required for us to move the needle on this. >> most of the tips that come into the fbi, they're filtered through the national threat operation center. that's in west virginia. and once they come in, they're assessed and analyzed, and depending on the threat, they could be passed on to local law enforcement. so wolf, it is possible that many of these increased tips that came in that first full week of august, they may have been passed on or really prompted some of those arrests that we saw that seemed like a spike in those arrests in the last few weeks of august. >> as they say, you see something, you say something. that's good advice for a lot of people out there. jessica, thanks for that report. >>> just ahead, we're going to get a new forecast on tropical storm dorian and