Part II: A Secret Past

Eric Wright insists he can explain what happened.

Back in 1980, gold prices were soaring and Wright said he came across a very attractive deal. He went to a motel in Richmond, Calif., in the San Francisco Bay area, to meet with his contact. The meeting took place six weeks after Marks' body was found.

"I was totally unaware of his death at the time," says Wright.

Wright said two gunmen attacked him in the motel parking lot the night of the meeting. Wright then claims that he has no idea what happened after that – except that he suffered serious memory loss.

"The last thing I remember in California was unlocking the door of my car," says Wright.

Wright's family reported him missing, and police discovered his car in a parking lot near the station. But several weeks later, Wright ended up in Colorado.

He blamed his amnesia on post-traumatic stress disorder, from his days as a Marine in Vietnam. The Veterans Administration even put him on full mental disability for this condition shortly before he was invited to testify before the grand jury in the Marks case. But Kathi says she never saw any evidence of this behavior that would support his claims.

Huber didn't believe his story either: "His use of the mental illness seems to be convenient for when he has something he doesn't want to remember or wishes not to talk about."

Investigators soon turned up a lot of evidence that Wright had planned his own disappearance. A copy of a book, explaining in elaborate detail how to create a new identity, was found in his office. And in the weeks before he disappeared, Wright followed its step-by-step instructions and became Steve Marcum.

Wright claims that he needed fake IDs in his business, and that creating Marcum had nothing to do with his disappearance: "I have never denied the fact that I disappeared. But it has absolutely nothing to do with the murder of Lester Marks. And that's the crime I'm charged with and that's the reason that I'm here."

But one thing is for sure: Lester Marks had gold in his possession about a month before his body was found. Investigators confiscated it in a raid, then returned it to him, and it was never seen again.

Prosecutors had testimony from two of Wright's former Colorado roommates that Marks' gold bars looked "kind of" like the ones Wright kept in his toilet tank. But the most important clue was a scribbled note found next to the phone in Marks' apartment. It had Wright's name and office phone number.

The victim's son, Ronnie Marks, is the only person who says he can testify that Wright and Marks had dealings. But Ronnie has a lengthy criminal record himself, mostly for theft and drugs.

48 Hours Investigates caught up with Ronnie minutes after he was released from one of his latest stays in prison. He claims that he talked to Wright on the phone and said, "He confirmed to me he was going to buy my father's gold."

But Wright's attorney charges that Ronnie, who was a suspect in the case for many years, may have killed his father. "[Wright's] a liar, he's a murderer, and he's a cheat," says Ronnie. "He's a killer."

Even though authorities won the preliminary fight to try Wright, the weakness of their case has them so worried that they offer him a deal. By pleading guilty to voluntary manslaughter, Wright will be able to avoid a murder trial altogether. It's a deal he quickly accepts.

This means that Wright won't be spending much time in prison. "A lot of people are going to be very vulnerable, including me," Kathi says.

"I accepted the plea to avoid what could have resulted in life in prison," says Wright. "I am an innocent man. I have been wrongly accused, wrongly convicted."

He's now a convicted felon, and is serving the maximum sentence of six years. But with good behavior, Wright could be out in only two years.

Has the search for her husband's secret past been worth it? "It's totally worth it," says Kathi. "He destroyed people's lives. I know in my heart I've done everything I can."

Just before his sentencing, she moved – yet again – to an undisclosed location.

Eric Wright has been ordered to pay $55,000 in restitution to the estate of Lester Marks, the man he admitted killing.