"Jack" was the media appellation; whether Sebastian is a first or
last name is left open.

I looked at who this historical figure could be, but no one else fit
into the area I wanted. It was a decision born of necessity, not whim. I
needed someone far enough removed not to have any current victims' families
still alive; someone known to a worldwide population (anonymous wouldn't
have worked because why would Sheridan have known about him, why should we
care, why should it resonate, and we'd spend time explaining what he did
that would have meant cutting out other material in the episode); the
other serial killers tend to have clear fates, whereas Jack vanished and
is thus "available" to us; visually that period makes for a striking
contrast to 2259.

And, again, you have to look at who he *was*...a fanatic, trying to
clean up Spittlefields (good cause) by hatred (wrong reason) and murder
(wrong means), the EXACT thing Delenn warns against at the very start of
the show. (Did you know there's a letter in the London Times for that
period that tries to explain the Ripper's motives as a cry ofr
(for) understanding about conditions in that part of London?) He felt he
was a divine messenger, learned he was not, and in bitterness has become
the single best inquisitor you could've had in that job.

Every single thing about Jack made him *perfect* for that role, as
mirror, menace and warning sign. So I used him. And I'd do it again.
You have to find what works best for the story, and do it.

jms