This is my first time posting on Websleuths, though I've been reading through the threads on the FLEK case for a long time now. Just never had anything meaningful to contribute! Bear with me on this one, it's a longshot but something to consider.
I came across the case of Deanna Criswell, a 16 year old girl who was found dead in Marana, AZ in 1987. There is a
Websleuths forum for Criswell. The
Wikipedia article for Deanna Criswell is a helpful summary of the case, too.
The suspected killer is William Ross Knight, who was 31 at the time. Both DC and WRK are from Spokane, WA I think. The only William Ross Knight I found record of in Spokane was born in 1956, and I am merely operating under the assumption that this is him. WRK relocated to AZ at some point, while in a "relationship" with DC. He purchased a bus ticket for her to come down to AZ to live with him, but she was never heard from again. WRK was never charged for the murder, and apparently died in 2005.
I found the blurb above from 1988 or 1987 from
this archived Arizona Republic issue.
Obviously this is a huge leap to connect this to FLEK. But I had been wondering if FLEK was an accessory to a crime, which was why she changed her identity and her appearance so drastically. I did kind of a lazy search about unsolved murders from 87/88 and that's how I came across DC. In reading a little bit about the case, any involvement on the part of FLEK seems unlikely as far as the murder goes, so I also wonder if this is the man she was escaping from. Her obit merely said that she was "from Scottsdale, AZ" (not Tucson, but AZ nevertheless.)
If she had any connection to the crime, as an accomplice maybe, maybe WRK set her up with the identity change. She may have been a witness or privy to the crime, but was too scared of retaliation so she took "witness protection" into her own hands? Many possibilities.
Maybe there are so little connections here that to even bring it up is too out-there, but it piqued my curiosity about FLEK's possible criminal history. Obviously some similarities in location and timeline are here, but that's about it. If this seems like an avenue worth pursuing, maybe somebody with more records access than I have (I'm not a member of any of the big Ancestry sites, etc.) could take a look.