In the July/August issue of American Photo, we named Getty photographer Brett Stirton's picture of a murdered silverback gorilla the "Photo of the Year." Now there's more to report about the image and its impact. In its July issue, National Geographic has an intriguing, absorbing feature tracing how Stirton and a writer returned to the scene of the crime, Virunga National Park in the Democratic Republic of Congo, to find out who killed the gorillas. The answers the pair came up with are shocking and disturbing. It's a must-read. The National Geographic TV channel will also air a documentary on about the story on July 1.