how to get user id of last person to touch a file

The history command can be used to identify the most recent change to a given file. But it returns the developer's full name, as opposed to user id (i.e. as used in username/password authentication). We need the user id for a tool integration we're working on.
How can I get the developer's user id, given a changeset UUID?
Thanks,
Scott
How can I get the developer's user id, given a changeset UUID?
$ scm history -m 1 common/antgalio/README
Change sets:
(4189) ---$ Scott Herzinger "enable turbo thruster..."
Thanks,
Scott