Still, he continued to evade direct questions about whether he had an intimate relationship with Levy.
"I think we're all entitled to some level of privacy ... It seems like in this country we've lost a sense of decency. I didn't commit any crime; I don't think I've done anything wrong," he told the prosecutor.
Salvadoran immigrant Ingmar Guandique is on trial for Levy's murder and an attempted assault on her in 2001. Prosecutors say Guandique had a history of assaulting female joggers in Rock Creek Park, where Levy's remains were found.
Throughout his testimony, Condit, a Democrat who represented parts of central California, referred to police investigators he believed were hounding him unfairly. He constantly referred to the media attention as a "circus" and said investigators were "out of line" when they demanded to interview his wife.
Condit also became emotional when he described how the Sept. 11, 2001, terrorist attacks wiped his name from the headlines. He said there were 100 reporters staking out his apartment that morning. After the planes hit, they were all gone, he said.
At the end of his direct testimony, prosecutor Amanda Haines asked Condit directly: Did you murder Chandra Levy? He responded "No." He also responded "no, ma'am" to the question of whether he had anything to do with her disappearance.
Haines never asked Condit if he and Levy had an affair, but she did ask why he never acknowledged an affair. His voice broke slightly, and he said it was "purely based on principle."
On cross-examination, though, public defender Maria Hawilo put the question to Condit directly: Did you ever have an intimate relationship with Levy?
"I have already stated I'm not going to respond to those questions," Condit said.
Hawilo persisted until Superior Court Judge Gerald Fisher told her to move on.
It is Levy's relationship with Condit that vaulted her disappearance into a national sensation nine years ago. Police no longer believe he had anything to do with Levy's death.
Condit testified Monday that he fully cooperated with the investigation, despite his concerns that detectives were "incompetent" and out to get him.
The only question he refused to answer, he said, was when a detective asked in an initial interview if he'd had a sexual relationship with Levy.
Condit said he responded: "If you can tell me why that's relevant, I can answer the question." He said the detective never answered and the interview ended.
Until that interview -- about a week after Levy went missing -- Condit said he never realized he was considered a suspect. He had called D.C. police at the urging of Levy's father to make sure they were taking Levy's disappearance seriously, and he assumed that initial interview with police was to provide him with an update on the investigation's status.
Condit testified that he last saw Levy a week before she disappeared and they discussed whether he could help her make some contacts with the FBI and other law enforcement agencies where she hoped to work. Condit told her he would help.
"We never had a fight. We never had any cross words," he said. Condit, whose hair has gone completely gray, was dressed in a blue oxford shirt and a sport coat. He described himself as retired.
Taking careful notes on his testimony was Chandra's mother Susan Levy, who has been in the courtroom throughout the trial and was fiercely critical of Condit throughout the investigation.
Prosecutors acknowledged in their opening statement that police failed in the Levy investigation by focusing on Condit to the exclusion of others, allowing Guandique to "hide in plain sight" as investigators failed to link Levy's disappearance with the attacks on the other joggers in Rock Creek Park, even though Levy had looked up information on Rock Creek Park on her laptop right before she disappeared.
Defense attorneys have said the investigation was bungled so badly that it has been impossibly compromised and Guandique has been made a scapegoat.