Sharon Rosenfeldt says the death of Clifford Olson, when it comes, will turn an important page for her. (CBC)

An Ottawa woman whose son was a victim of serial killer Clifford Olson says the boy’s death in 1981 took a terrible toll on his family.

Following news that Olson may be close to death himself, Sharon Rosenfeldt talked about the pain he caused her and her late husband.

"This will never end for me. But it's a page I can turn once I do know that he has passed away and can't harm us or anybody else ever again," Rosenfeldt said Wednesday.

She said the death of her son Daryn Todd Johnsrude was particularly devastating for her husband Gary, who died a few years ago of brain cancer.

Near the end of his life, she said, Gary could not recognize his family. But he repeatedly screamed the name of Olson.

"In fact, his last words were of Olson. So this is really quite emotional for us. It's quite bittersweet," she said.

"I guess my son summed it up. He said, 'You know, Mama, Clifford Olson may be dying, and he will be dead. It won't bring Daryn back. We haven't got Daryn. But … the biggest thing is he won't be able to hurt us again. After 30 years, he won't be able to hurt us.'"

A few pictures and painful memories are all that Rosenfeldt has left of Daryn, who was kidnapped and murdered by Olson in the spring of 1981 in Coquitlam, B.C.

Daryn was 16 at the time, and he was Olson’s third victim in a series of murders that would eventually include two children and nine youths.

Olson was sentenced to life in prison, a sentence that is likely about to end. Rosenfeldt said families of the victims have been told that Olson has cancer, and he may live only a few more days.

Olson is now 71 years old. He's been serving his life sentence in a maximum-security prison in Quebec. Now he's been transferred to a Montreal-area hospital where he will live out his final days.