Well, this CPAN module might be part of your solution: Lingua::EN::MatchNames

But as other people have pointed out, you're going to have deal with a substantial amount of ambiguity about what a valid human name looks like.

If you do some web searches, you can find some on-line white pages like this one, for example: Maryland Government Employees. You could use LWP to feed candidate strings into this form, and if it returns some hits, you know it's not too unusual as a human name.

Using this algorithm, I can confirm that "Brenner" is a valid name, which is a relief.