Botchie
Striker
I don't know if they've revealed the entire cast list, but obviously we would only see those two actors in flash back scenes really.He was found and the state of him led the family to believe he was unfit to take over the business iirc. In steps William and the rest is history. There's a line somewhere in S1 about it.
I think the DNA thing however opens the door for any 'dead' character to return as a host......that was probably a wise choice...
so does that mean the MiB will be in the loop as to the extraction of guests DNA? I seem to recall near the end of the last series he was talking to someone saying the "board" has given the go-ahead - so he must be active in the goings-on of Delos?