Transcript for 'Start Here' podcast: Active-shooter scenarios on the rise
And the aftermath of these mass shootings here in the US has become. Unfortunately familiar at subject ABC's Brett Nokia has been talking about Brett good morning. A yes you know as devastating as this shooting was the di tale sounds so distressing with familiar. And of course it wasn't always this way Chief Justice correspondent Pierre Thomas has studied gun violence more than anyone at ABC news so asked him. How do we get to the point were this feels normal. If BS started studying active shooter scenarios in 2000. In the first seven year period they looked at. From 2000 to 2006. We were averaging about. Six point four. Active shooter scenarios. Per year. In the next seven year period they looked at it was up to sixteen. Last year there were thirty. Active shooter instance that the FBI study. Five times the pace but when they first started looking at this issue. And part of the reason for that he says is that he shooters are studying each other learning from their infamous predecessors. And sources tell ABC news that is exactly what happened in San a thing I hear that entire conversation on start here later this morning. Check it out on apple podcasts for the podcasting app and us Diane.
This transcript has been automatically generated and may not be 100% accurate.