Why do some reporters say, "This reporter"...?

Question

when they're referring to themselves in a live broadcast on the scene of a news event?

Answer 1

It's a little old-fashioned, but it's obviously a way of indicating he or she was on the scene. I think Dan Rather used to do it.

No one uses the editorial "we" very often, either. Words change in usage over the years.

Answer 2

To sound more professional I guess.

Answer 3

Can't spell "I"

Seriously though.  The reporter is meant to be a fly on the wall, not part of the story.  It's a rather phoney traditional way of distancing oneself while claiming the certainty of experience.