-- The FBI searched Ford Motor Co.'s world headquarters while investigating one of the automaker's engineers and seized listening devices, computers and financial records, according to search warrants obtained by The News on Thursday. A lawyer for the mechanical engineer said Ford's security team feared she was stealing trade secrets by hiding secret recording devices in conference rooms at the Dearborn automaker's headquarters, nicknamed the Glass House. Court records that would explain why the FBI had probable cause to search Ford and the engineer's home are sealed in federal court. The government's lawyer on the case, Assistant U.S. Attorney Jonathan Tukel, heads the National Security Unit in Detroit, successfully prosecuted underwear bomber Umar Farouk Abdulmutallab and specializes in cases involving espionage, counter-terrorism and terrorism financing, among others. Searching a Fortune 500 company's world headquarters instead of issuing a subpoena is a rare step and could indicate investigators were worried about someone destroying evidence, said Peter Henning, a law professor at Wayne State University and a former federal prosecutor. "If it's an economic espionage case or trade secrets case, that rarely involves one individual," Henning said. "So the concern is if you send a subpoena and ask for recording devices, those things can be erased." The U.S. Attorney's Office and FBI declined comment Thursday. A Ford spokeswoman, Susan Krusel, declined to discuss the investigation in detail, but said Ford is not a target. "Ford and the FBI are working together on a joint investigation involving a former employee," she said. "As this is an ongoing investigation, we are not able to provide additional details." The search warrants show the FBI searched Ford's headquarters July 11 and agents had permission to search the entire facility. Agents were authorized to seize digital and electronic recording devices given to Ford representatives by Wyandotte resident and former Ford engineer Sharon Leach, emails and other records, according to a copy of one search warrant. The search at Ford's headquarters came three weeks after FBI agents raided Leach's home on St. John Street and seized more than two dozen items, according to a search warrant inventory obtained by The News. Leach, who has not been charged with a crime, declined comment Thursday after opening the front door of her yellow, two-story colonial. "I'm not gonna talk," said Leach, 43. "I'm a private person." Until recently, Leach was a mechanical engineer with a doctorate at Ford, where she had been employed for about 17 years. In April, she was included on a panel of experts talking about hybrid vehicle performance at the 2014 SAE World Congress at Cobo Center. She was fired recently after Ford's security team discovered recording devices planted in the automaker's meeting rooms, her lawyer Marshall Tauber said. "She has done nothing wrong nor been accused of doing anything wrong," Tauber said. Leach admitted hiding the devices under tables to help her transcribe meetings, her lawyer said. "It didn't involve anything of a spying nature," Tauber said. "She wanted to record conversations of meetings she attended but didn't know how to do it. She was insecure about her note-taking." The devices were installed before meetings but could not be easily removed, her lawyer said. The audio devices were left in the conference rooms and unintentionally recorded other meetings. "It was very difficult to remove them when other people were in the same room," Tauber said. "That leads to Ford Motor security finding this activity suspicious." The devices were never installed in the Board of Directors conference room, he said. "She was a low-level engineer," Tauber said. "Her salary wasn't even $120,000." Leach was fired in June after she admitted using the devices, her lawyer said. "She had one in her purse and said 'here it is,' " Tauber said. In all, Leach gave Ford security eight Sansa recording devices, her lawyer said. Those are the same devices listed on the FBI's search warrant on July 11, Tauber said. "Ford had the devices since prior to the day she was dismissed in June," Tauber said. "Now, Ford may not have released them to the FBI or said 'give us a search warrant.' " Leach did not intend to share the recordings with anyone and erased the files after listening to the audio and revising her notes, Tauber said. "I think you're dealing with a person who was seeing how sharp the new kids are and maybe feeling a need to keep up with them," Tauber said. "And maybe she realized that she's not as attentive as she once was and needs a little assistance. Maybe her memory was failing her on the technology end but she didn't want to admit it." The FBI raided her home June 20. "They don't believe her," Tauber said. During the search at Leach's home, agents seized more than two dozen items, including several desktop and laptop computers, a credit card, thumb drives and financial records, according to the search warrant receipt. "They want to know if she is suddenly coming into more money than her salary shows," Tauber said. "My client tells me they are not going to find anything unusual whatsoever." Agents also seized a buy.com shipping bag and invoice. The website is an online shopping mall owned by Rakuten, a leading Japanese e-commerce site. Other seized items included work documents and tax records. Leach's neighbor Bethany Tate was watching June 20 as about a dozen FBI agents searched the house two doors away. An FBI mobile unit was parked in the neighborhood and agents spent about five hours inside Leach's home, Tate said Thursday. "It was puzzling," said Tate, 36, standing on the front porch of her home and holding her infant daughter. "You don't expect to see the FBI with guns in your neighborhood. I wondered 'is she dead?' " Agents wouldn't discuss the search, she added. Leach refused to sign the FBI's receipt listing items seized during the raid, according to court records. So agents left copies on her dining room table.