William Blackstone (English jurist, judge and politician of the eighteenth century)
In his 'Commentaries on Law of England', Sir William Blackstone defined Crime as: “An act committed or omitted in violation of Public Law forbidding or commanding it".
Paul W. Tappen (Lawyer, criminologist, educator and author of the USA)
Crime means: "An intentional act or omission in violation of criminal law, committed, without defense or justification and sanctioned by law as felony or misdemeanor