[frank ballenger]

You should look at this old book:

Incredible Coincidence: The Baffling World of Synchronicity
Alan Vaughan. 1979. A book with 151 numbered cases with sources. Here’s one. A man mentioned in an article in the London Sunday Times, May 4, 1974 was driving in London and a car ran into his. The policeman asked for ID. The man said he was Ian Purvis and showed his ID. The officer asked the other man his name. “Ian Purvis.” “I don’t think we have time for silly games, show me your ID.” It said Ian Purvis. Both men.

Or this one from 2022.

Meaningful Coincidences: How and Why Synchronicity and Serendipity Happen By Bernard Beitman.

[Jamestown1630]

I've read Jung. Even if these missing/dead people are connected, I don't think this qualifies as his concept of 'synchronicity', which refers to meaningful coincidences without causal connections.