However, it was then decided that Koecher was not reliable enough to be a triple agent and was likely to defect and return to Czechoslovakia. On November 27, 1984, the day after the couple sold their apartment and hours before they were scheduled to fly to Switzerland, Koecher and his wife were arrested in New York City. Koecher was held on espionage charges and Hana Koecher as a material witness. The arrest of the two agents was released to the media. U.S. Attorney Rudolph Giuliani led the case. The case on his wife, Hana, a purported diamond merchant but actually a courier for the StB from 1974 to 1983, had been bungled and would not result in a conviction, so the prosecutors allowed her to gain immunity in return for information against her husband Karl Koecher.