Roberts is professor of History at Purdue University in Indiana. Roberts has been active as an expert witness for the defence in 25 tobacco-related court cases. Roberts has acknowledged in 2010 during a deposition pertaining to In re: Engle Progeny cases that he had made around $500,000, charging $300 hourly for his tobacco-related litigation-driven work. In testimony given in court by Roberts in that same case in 2012 that he had made over $900,000 as an expert witness for the tobacco industry.
 See deposition of Randy Roberts, July 15, 2010, In re: Engle Progeny Cases. Westlaw reference: 2010 WL 6546729.
 See testimony of Randy Roberts, June 7, 2012, In re: Engle Progeny Cases. Westlaw reference: 2012 WL 3450319.