On the copy of this story that appears here:
http://crash.com/fun/texts/vaxen-dont.html
it is atrributed as such:
'The author of this piece is Jack Harvey,
harvey(at)eisner.decus.org, and
it was originally published under the title "The Immortal Murderer" on
January 18th, 1989 on DECUServe, the DECUS member bulletin board.'
--Pat.