I Googled "Benjaman -Doe -Burger", thus eliminating any reference to this news story, and found a number of "Benjamans", both first and last names.

I can well imagine a situation where either

1. He was formally named BenjamIN when born, and somehow picked up the -man spelling as a nickname in his youth
    OR
2. His family name is Benjaman, so spelled, but that he has been addressed enough by that family name that it stuck in whatever was left of his memory.

I suspect that I was far from the first to think of Googling "Benjaman", so I don't suppose the first and last-name Benjamans whom I found are any surprise to the FBI and other searchers.

Dave Oesterreich