Transcript for Schizophrenic Sign Language Interpreter: Was Obama at Risk?
We're going to get to more fallout from the fake sign language interpreter at nelson mandela memorial service. The fact that a schizophrenic with a checkered history could get so close to president obama and other world leaders raises questions for the secret service. Pierre thomas has more from washington. Reporter: There's no way around it. In hindsight, this was a scary situation. And the president was potentially at risk. Watch closely as the president of the united states makes hiss way to the podium to give his speech during the nelson mandela memorial service. The president almost has to squeeze by the sign language interpreter to get to the microphone. Watch again. They're shoulder-to-shoulder. The interpreter is only a couple of steps away from the president throughout his nearly 19-minute speech. Closer than any secret service agent. Sometimes I will get violent on that place. Sometimes I will feel things. Reporter: We know that he may not have been qualified to sign. And he claims he has a history of mental illness. He even says he was having delusions during the event. I see angels come to the stadium. Reporter: A huge embarrassment for event organizers and a major breakdown in security for the president. The secret service responded thursday, saying the south african government, the host country, was responsible for vetting the event staff. But the vetting by south african officials was clearly deficient. And one senior official in the country said, that the company that provided the interpreter appeared to have vanished. Will they learn from this? You bet they will. They will make very certain that there is never a situation like this again. Reporter: It could pose security headaches. At one point, the president's motorcade got stuck in traffic. Thankfully nothing happened. Imagine in this man had attacked the president. How could that guy with that background be so close to the leader of the free world? That's the thing, pierre. There's so many questions about this man's background. Is the secret service dropping this now? Or doing more to investigate? Reporter: My sources say they're largely department on the south african officials to get to the bottom of how this happened. But clearly, there will be reviews internally. Pierre thomas, thanks very much. We'll talk about all this and all of the politics sunday on "this week."
This transcript has been automatically generated and may not be 100% accurate.