 as investigators are beginning to try to piece it together of who was it and what was the motivation, and were there any warning signs, were they connected to anything? All of that we don't know yet. But security at the RNC, as Stephen talked about, is being ramped up. John Carl is there already, ABC's John Carl, and he's been seeing it firsthand as this unfolded today because he was at the venue in Milwaukee, and he describes it like this.