Transcript for ISIS Says Two of Its 'Soldiers' Attacked Texas Cartoon Contest
Claiming responsibility ice is now seeing two of its soldiers carrying out that failed attack on a Texas court event which injured a security guard. This you gunmen targeting that event for future and controversial cartoons of the Prophet Mohammed. The terror group released this statement today on Twitter saying an even bigger and more bitter attack is not far away. Hi everyone I'm Carolyn Costello in New York for the first time since that attack we are hearing from the mother amid dear Sufi one of the gunman in that shooting. She's opening up about the warnings she gave her son that elephants in saint. And getting caught up in extremism. It. Let's bring in ABC news and prime terror analyst Brad Garrett Brad thanks for being with us. When a gunman racist sympathizers. Or operative. Well. You know based on the sort of lack of organization. That it appears to have occurred where these two and he it's almost like. We want to pull something not we really don't have our act together to do it. We have we have inspiration to do it but clearly he did work out. At all. Some more like sympathizers of sounds like you're saying and officials say that they knew at least one and he is gunman pretty well it was on their radar. How does this happen. Because. There are tens of thousands of people in this country that that. Sort of a loosely fit mr. Simpson's profile. And so you have to draw a line someplace there are only so many people. So many surveillance folks so many wiretaps you can put up at any given time. And so as a result you have to call on what intelligence you have. Clearly they've known about him. Four and number appears up to ten years. He was previously charged for lying to the FBI about apparently wanted to travel to. Somalia to join Al should Bob. But they place him on probation. So in less you have new intelligence. That's the tricky missed the cat and mouse game here how do you decide who you're actually going to put physical surveillance on. Because it takes a lot of people just to watch one person. And what is the process for monitoring people like these persons of interest as it expands and how often their files reviewed. It really depends on the person I mean clearly are people that have their cell plants tap may be their hard line staffed. Bear there watched through stationary cameras and certain locations may be outside their residents or place them. Employing that are places they gather. And then it on some occasions there are people that they're physically watch. But that's a very small number digging in a day out. And so as a result. And less you have information for example there appears at least on the surface. To be some connection between mr. Simpson. In these most recent arrests. In Minneapolis and San Diego. I don't know any of the specifics yet but for example did they tied his name in some way. With those folks. News that still needs to be explored obviously. But it's that kind of information now just because they he might have be connected to that group doesn't mean anything other then. Is there additional information that talks about him dean operational are actually going to a place like this convention. In Garland Texas and committing this act. Obviously it didn't that or they would have been there. So. This these type of individuals despite how sloppy they were and I'll ultimately got killed. That your they're most concerned about you don't know about them until then back. They act. Right cracked ice is tweeting that and even bigger and more bitter attack is on the way hot only. Karen terrorism officials weighed the risks of these threats how real are. Well I think you have to take them for their face. Because let's look at this you know did anybody. Inside the the working apparatus of ice just tell these two guys to go shoot up. This image listener my guesses and may be but this was. You know they aligned themselves what ices over reply crisis. And they'd be taking these actions themselves. So if you using that format how many people out there are just like them. Who don't like the United States who have and alliant and vices or al-Qaeda or someone like them. Pump and you don't know if you don't have that pieces intelligence it's very difficult and even when you do. Like mr. since Simpson like hazard map Brothers the Boston Marathon bombing. We knew about them but we didn't know about them becoming operational. And that's the tricky key component to this. Is having hit in front of everyone of these people. And as I've said before numbers are catching up with us at least you may be a great example of that. Rank and you know as you said. There's no evidence that ice is directed at this targeted attack may be just inspired able what is the benefit to the terror report claiming responsibility. Because they're trying to show look. We can launch people anyplace we want we really would have to be there were disarmed we gonna do it which is true crisis has put the word out. Now if you live in the United States or some other western country that they don't like. We want you to attack when you can. So it's a combination of attack attack in place or come join us in Syria and Iraq. And it don't be surprised if you see more of these type of attacks. As we go into the future. And is the bottom line here that crisis is now carrying out terrorist attacks in America. I think that has to be accurate whether this was aspiration all they align themselves devices. They committed it or crisis told them to get do it looks and gonna guess is not true but it might be. Yes you're going to see more this because. It seems like every week we end up talking about some case many times it's a flopping its foil. But this is something that's going to continue to grow. And I think you're visually become potentially a bigger problem for us okay ABC news crime and terror analyst Brad Garrett with us Brad thank you so much. And you keep up with the story in real time I downloading the ABC news app and storing this story for exclusive updates on the go I'm Caroline Costello in New York.
This transcript has been automatically generated and may not be 100% accurate.