I have the dubious distinction of having been a witness to both a stoning-to-death in Nigeria, and a public execution of a (presumably) adulterous couple in Riyadh, Saudi Arabia.
The latter episode: Bill Stewart, then of Time Magazine, and I happened to be in Riyadh, he for his magazine, and I as a foreign correspondent for the New York Times. I don't recall the exact circumstances, but we found ourselves in a square where the couple was brought out of vans. They seemed to be ina daze; I'm sure they were drugged. Each was made to kneel, and then shot in the head. I don't think the crowd applauded.
The Nigerian episode was in a small village, north of Kaduna, I think in 1979, when I was Africa correspondent for the Times. The man was said to have been found guilty of murder and theft. His hands and feet were bound, and a small group of men began pelting him with what looked like especially sharp small stones. My suspicion was that they were the "executioners," because they aimed for the man's head, which quickly split open. I did not hang around for the coup de grace.