Aerospace engineer Noshir Gowadia, accused of selling key American military technology to China and other countries, decided not to take the witness stand in a hearing on how federal investigators obtained evidence and detailed admissions of guilt from the Maui resident.

Gowadia's lawyers have attacked the admissibility of much of the evidence the government intends to use against Gowadia in an espionage case set to go to trial here later this year. It is believed to be the first spy trial held in Hawai'i.

Handwritten statements from Gowadia, produced during nine days of what federal agents said were voluntary "interviews" with him at the Honolulu FBI office in 2005, contain confessions of "treason" and other crimes.

Gowadia's legal team contends the statements were coerced during "interrogations" by federal agents who allegedly threatened Gowadia with the death penalty and said they would lock up his wife and family members if he didn't cooperate.

But the two investigators who questioned Gowadia before his arrest adamantly denied using any threats against him and said they wouldn't have done anything that would have caused him to stop talking to them.

FBI Special Agent Thatcher Mohajerin said that during the course of the interviews, he didn't have the authority or the desire to arrest Gowadia.

"We had a great relationship. He was talking to us. He was giving us really good intelligence," Mohajerin told assistant U.S. attorney Ken Sorenson at a hearing last week.

"It was a pretty exciting time of my life," Mohajerin said. "This was an important case."

Joseph Williams, a special agent with the Air Force Office of Special Investigations, also testified that Gowadia talked freely.

"I think he really wanted to contribute," Williams said. "We had a pretty good rapport."

But Williams said he was "shocked" by Gowadia's admissions.

"I've been in this business more than 33 years and I've never heard anything like this before," Williams testified.

At one point, Gowadia asked "what was going to happen to him," Williams said.

"I told him clearly what he did was very serious, but I couldn't make any promises," Williams continued.

Gowadia continued his confessions to the agents that day and wrote a statement that described in detail his efforts to help the People's Republic of China design a "stealthy cruise missile."

In the statement, Gowadia wrote, "On reflection, what I did was wrong to help PRC make a cruise missile. What I did was espionage and treason because I shared military secrets and shared my technical knowledge, which I had acquired over many years working with U.S. systems like B-2 (stealth bomber), A-12 (attack aircraft), TSSAM (cruise missile), F-18 (attack aircraft) and others."

Gowadia said he made the statement "so that I can correct the harm I have caused and move on the next phase of my life, which is retirement."

He wrote that no one had threatened him and he knew that "I could call a lawyer, stop talking or leave."

During the course of the interviews, Gowadia stayed in Waikiki hotel rooms rented by Mohajerin, who used a "covert identity" to pay for the transactions, the agent testified.

After the interview in which Gowadia wrote out his "treason" admission, his reservation at the Ala Moana Hotel expired and Gowadia was moved to a lower-quality hotel, according to court papers.

After Gowadia jokingly complained to the agents "that they were just like the Chinese, once they got what they wanted, they put him up in a less-desirable hotel," Mohajerin found him a room at the upscale Prince Hotel, according to court papers.

Chief U.S. District Judge Helen Gillmor asked defense lawyers Birney Bervar and David Klein to file final memos on the evidence suppression issues by Jan. 29.

Prosecutor Sorenson will file a reply memo early next month and Gillmor will rule after that.

She is also considering defense motions that question the legality of searches conducted under the authority of the Federal Intelligence Surveillance Act.

Federal agents had Gowadia under investigation for nearly two years before his arrest on Oct. 26, 2005.

Still pending as a separate court action is a federal effort to seize Gowadia's palatial home on a Maui bluff overlooking the ocean.

A Washington, D.C., law firm that represented him for a time in the espionage case has also laid claim to the house, alleging that he owes the firm more than $1 million in legal fees. Gowadia has denied that claim, alleging the firm committed malpractice in its representation of him.