Crypto doesn't work like that. There is no 'helping' someone find their lost key. Not in the sense of it taking a Crypto expert to help that is. If your key it was on a usb drive, or written down somewhere and you "lost" it, you would hire a private detective before you'd reach out to a crypto expert to find it.
A "key" to a "wallet" is typically a long randomly generated string of numbers and letters.
(e.g. 1E99423A4ED27608A15A2616A2B0E9E52CED330AC530EDCC32C8FFC6A526AEDD)
On top of that, the identifier to the wallet is again a long randomly generated string. This one is harder to lose, because you can store it publicly, and share it etc, but if you do happen to lose it, there's no getting it back.
I find it extremely unlikely that he was murdered because he failed to help someone restore/find a lost key.
Source
Also, this is a generalized and simplified explanation.
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For people who have been asking about John's bitcoin stash, that would be very interesting to see. FWIW, here is the wallet address with 1 BTC that John set up a
treasure hunt for.
157dpLJgAAKugukKz8UwBHapM4idyZvnLc. You can see it still has 1 BTC in it. We will also be able to see if someone sends the BTC anywhere. He said he would take the secret to his grave (see description for video 1).
Here is
video 1 in the announced series of 10 videos. Only 5 were ever released.
At the end of the first video this string flashes at the lower right of the screen 5JYx.
The other 4 videos have no such easily identifiable snippet.
Here are the youtube listed release dates for the 5 released videos.
Video 1 June 22, 2021
Video 2 July 9, 2021
Video 3 August 19, 2021
Video 4 September 11, 2021
Video 5 March 29, 2022.
I find it curious the release timing. I wonder what happened that he stopped releasing videos last march.