A Canadian man who had been ready to plead guilty in connection the 1982 death of his then-girlfriend has changed his mind.

Jaroslaw "Jerry" Ambrozuk was to be sentenced Wednesday in a Montana courtroom on a charge of negligent homicide. In exchange for his guilty plea, entered on Feb. 1, Ambrozuk was to receive a suspended sentence.

But he was to be handed over to federal authorities to face a federal indictment for living in the United States illegally for the last 24 years. And when it was revealed that they could then extradite him to Canada, where U.S. court conditions don't apply, the deal was off.

He will now go on trial in the death of 18-year-old Diane Babcock.

"You just can't do things like that. It's not right," said Ted Babcock, Diane's father, in reaction to the change in plea.

Twenty-five years ago, Jerry and Diane were high school sweethearts. Ambrozuk, 19 at the time, rented a plane. Weeks later, searchers found the plane at the bottom of Bitterroot Lake near Kalispell, Mont. with Babcock's body still strapped in.

"It was horrid, horrid. She didn't deserve to die like that," said Jodi Ann Stephen, Diane's sister, in court on Wednesday. "She was such a good person."

After the crash, Ambrozuk was nowhere to be found. He would later phone a friend and say they had planned to fake their deaths and elope in the United States, but things went wrong and he was unable to free Babcock because her seatbelt was jammed.

No one heard from him again.

Police were always suspicious of foul play, noting that Babcock's seatbelt wasn't jammed as Ambrozuk had claimed, and cash and Ambrozuk's belongings were missing from the plane.

A break in the case came with Sheriff Jim Dupont, who worked on the original investigation of the crash and who is now retired, got a call from Texas from a former girlfriend of Ambrozuk.

"He had evidently told her portions of the story," Dupont told Canada AM from Kalispell.

"She was concerned about it, looked it up on the Internet and found my name associated with the story and gave me a call. And as soon as she started telling me about it, I knew it was more than likely that this was he."

Last summer, Texas police went to a suburban home to question a man going by the name of Michael Lee Smith.

"His reaction was surprise. There was no incident at all, he didn't run from the police. He immediately surrendered there at the doorway," said Rick McDonald of the Plano, Tex. Police department.

Neighbours assumed Ambrozuk, now 44, was wealthy because he drove an expensive car -- an $88,0000 Dodge Viper.

Ambrozuk has said he went to New York City after the crash, earned a college degree then prosperered with a software development company he founded.

In court, Stephen expressed the hope that Ambrozuk gets jail time.

"The only reason I say that is there's no other place where he'll learn a lesson," Stephen said.

With a report from CTV's Julia Foy