I'm sure he was a reporter with ITN. I vaguely remember him from those days but it was the 'Tonight' programme (this must be an update) that brought any memories back.
Very sadly this was probably Carol Barnes' last contribution to TV - and she was very good. Good enough to have had a new career as a documentary-maker. Her daughter pre-deceased her a few years ago so it's a sad story all-round when you consider Mr Mitchell's decline as well.