Katherine May Wilson (bottom), seen with her sister on her shoulders, disappeared in 1970 in Kirkland Lake, Ont. (Submitted by Aline Wilson)

More than 38 years after a 12-year-old girl went missing in the Northern Ontario town of Kirkland Lake, her cousin has been charged with her killing.

Ontario Provincial Police confirmed Wednesday that Barry Vincent Manion, now 60, has been charged with the first-degree murder and abduction of Katherine May Wilson.

News of the arrest was a relief for Katherine's mother, Aline Wilson, who said she hasn't been able to sleep properly since her daughter disappeared while walking home from a gas station convenience store on Oct. 10, 1970.

"I jumped to the ceiling. I'm so happy," Wilson told CBC News. "I never gave up hope."

Although Wilson said she had feared an arrest would never be made, she said she wasn't surprised when police named Manion as their suspect.

On the afternoon Katherine went missing, she was picking up groceries for her mother. Katherine called home just before 5 p.m. to ask whether she could buy a can of pop or a bag of chips with the leftover change.

Wilson agreed, and her daughter said she was going to walk home. Wilson said she would have Katherine's two sisters walk out to meet her halfway. The sisters went, but Katherine never showed up.

Police searched for her for weeks using dogs, helicopters and boats, but Katherine was never found. Her body is still missing.

'Now we'll have closure'

The OPP renewed interest in the case three months ago, issuing a press release asking for information and offering a $50,000 reward.

"I am proud of the dedication and the relentless pursuit of justice by the members of the OPP and appreciative of the assistance that the family of this young girl and the public played in this investigation," OPP Commissioner Julian Fantino said in a written statement.

Police have not said what led to Manion's arrest. Wilson said she is meeting with police Thursday to learn more details.

"Now we'll have some closure," she said, her voice cracking. "It's been a long time not knowing."

She said her only fear is to find out exactly what happened to her daughter, and learn about suffering she might have endured.

Manion lived in Kirkland Lake when Katherine went missing but most recently resided in London, in southern Ontario. He will appear in court in Haileybury, near Kirkland Lake, on Friday.