about whether I had savings, what I did with it," Mang said. "He said we're trying to get to know each other better" and called it due diligence. Mang said she didn't know what due diligence was and "thought it was just a cute nickname he had for me." And so Ms. Mang invested about $62,000 in Oce, a Dutch maker of photocopiers, which prosecutors say Mr. Ammann knew was set to be acquired by Canon. The deal was made, the stock rose, and prosecutors say, Ms. Mang made off with more than $100,000 in ill-gotten gains. What she appears not to have done is due diligence of her own: While Mr. Ammann was passing inside information to Ms. Mang, he was sharing the same tip with another woman.