Melvin received a Bachelor of Commerce degree with Distinction in 1977 and a Bachelor of Laws degree in 1978, both from the University of Saskatchewan. He was called to the Saskatchewan Bar in 1979 and achieved his Chartered Accountant designation in 1981.

Melvin is a Fellow of the Institute of Chartered Professional Accountants of Saskatchewan. He is a past Governor of the Canadian Tax Foundation, is past Chair of the Discipline Committee and a past member of the Professional Conduct Committee of the Institute of Chartered Accountants of Saskatchewan.

Melvin has volunteered with numerous charitable and non-profit organizations including serving on the boards of the Saskatoon Community Service Village Inc. and the Saskatchewan Catholic Health Corporation.

Melvin was involved in the initial public offering of Potash Corporation of Saskatchewan Inc. and in the organization of Ag Growth Income Fund.