WASHINGTON -- UFOs were the topic of a panel discussion Wednesday night at American University, and one of the speakers used the occasion to reveal evidence he called a "smoking gun." "We have come into possession of a couple of Kodachrome color slides of an alien being lying in a glass case," author and researcher Thomas Carey told the near-capacity crowd in Abramson Recital Hall. He's been researching the 1947 Roswell incident since 1991.