Esmond Bradley Martin, one of the world’s top investigators into the illegal trade of ivory and rhino horns, was found stabbed to death in Kenya over the weekend. Martin’s wife reportedly discovered the 75-year-old American dead at his home in Nairobi on Sunday. He was writing up a report on a recent trip to Myanmar at the time he was killed. Martin formerly worked as a special envoy for the United Nations on rhino conservation. He was best known for his undercover work. Kenyan police have said they suspect the killing was a botched robbery attempt, but have made no arrests yet in the case. Last week, Hong Kong announced it would ban the sale of ivory beginning in 2021; China’s ban on all sales went into effect at the end of December.