If someone's ssn was used after their supposed death, and no other identity attached to that number...\

does that mean there is a possibiliity this individual is still alive and that they used their ssn before the advent of the internet? My friend died mysteriously in 1984 and I recently found that their ssn was used three times, twice in 1986 and once in 1990. The addresses ociated with the results, were three addresses where he once lived, the first in california, the second where their financial handling was done, and third a made up address in the town he grew up in..he was known to make up addresses and change his name before he died, he came from a wealthy family.. is this a sign he's still alive and if so how can i find him?