He moved to Cape Town, South Africa in the mid-1980s to work for Bnei Akiva, a Jewish Zionist youth movement.
[citation needed] In early 2004, Karni was accused by the United States of being part of a conspiracy to sell stolen nuclear material.
Chief Judge Thomas F. Hogan ordered Karni released on US$100,000 bail to Silver Spring, Maryland, having agreed to waive diplomatic immunity and wear an electronic surveillance device, but the US Government moved to have that ruling overturned.
Karni was accused of selling 200 triggered spark gaps to Humayun Khan, a Pakistani man believed connected to a larger terrorist group in Jammu and Kashmir.
[1] On August 4, 2005 Karni was sentenced to three years in prison for the sale of restricted equipment to companies in India and Pakistan.