Family of suspected victim says there's no closure in Arthur Ream's death

It's been over 16 years since suspected serial killer Arthur Ream was sentenced to life in prison for the murder of Cindy Zarzycky almost 40 years ago.

Ream died of cancer last month in prison, but the investigation into 5 different cold cases continue. Officials say all of them have roads that lead to Ream.

Even after his death, the sister of presumed victim Kimberly King says she isn't sure it was Ream who was responsible for her sister's disappearance.

“I think it’s a very strong possibility or probability but I don’t know 100%,” says Konnie Beyma.

12-year-old Kimberly King went missing in 1979, disappearing into the night during a sleepover. After decades of investigation, police are unable to say who took her or where her body is.

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Missing in Michigan: New search for answers in disappearance of Kimberly King

Detectives on the case say all roads point to Ream, but they don't have enough evidence to say for sure.

But Kim's sister isn't convinced Arthur Ream is completely innocent either.

After receiving the following letter from Ream in the mail in 2022, Beyma says she isn't certain her sister faced the same demise as Cindy Zarzycki at the hands of Ream.

WATCH: Beyma reads the letter she received from Arthur Ream below

Sister of Kimberly King reads letter she received from Arthur Ream

“Dear Miss Beyma, I hope this letter finds you well. I'm writing to you because I understand how you feel. Not a day goes by that I don’t miss my son Scott. I know it’s not the same. I know where Scott’s at. And you have no idea where Kimberly is. I hope you understand when I say I had nothing to do with your sister’s disappearance. If you have any questions, please write and ask. I’ll write you back when I’m feeling better. Take care and please don’t listen to the detective from Warren. Art Ream.”

The question Konnie says she wrestles with now: was the letter genuine, or was it Arthur Ream's last attempt at twisting the knife in the heart of a victim's sister?

“I don’t know. I didn’t have enough communication with him to develop that feeling,” she says.

For Kim's family, there is still no closure. But Konnie says she rests easy knowing detectives continue to work tirelessly to bring her sister's disappearance to justice.

“If there was anyone out there that was fearful of Art Ream now that he was passed if you know anything, just if you had a conversation where he references Kim, maybe he didn’t make any admissions maybe he just made a couple comments, we don’t know what small thing may help,” she says.