LOS ANGELES – The FBI knew about Chi Mak's retirement plans, what his dining room looked like and what he allegedly took home from work. The 66-year-old engineer for a Southern California defense contractor and his 57-year-old brother, Tai Mak, were under surveillance for months. Agents tapped the Maks' phones, planted listening devices in their cars, sifted through their trash and installed a closed-circuit camera above Chi Mak's dining-room table. Investigators suspected Chi Mak was taking restricted documents about naval technology from his job at Anaheim-based defense contractor Power Paragon and passing them to his brother, who was going to...