Question is: What makes an "expert witness"
Answer Some sort of qualifications in almost any subject, a couple of published papers and then sign yourself up with a "register" such as http://www.jspubs.com/
Oh and the money you can claim for your "expert" opinion is considerable.
Whoopee! I thought I'm up for that......
Then I discovered that what they really wanted was £166 of mine!
Ho Hum...
Yup and you don't even have to be expert at anything ~ other than bulls hit of course.
Quickest way to make money BTW is to fail at your chosen profession/career and use the knowledge gained to start a "Register" or "Governing Body" or similar and charge everyone else who beat you in business to join it. Think ABTA etc and you've about got it. Full details on this wonderful business opportunity + details of copyrights, franchises etc can be obtained from Snoopy Inc c/o my email address published at the side of this post.
And I am not even in Nigeria