So we know Lance Armstrong lied. According to Lance Armstrong his Tour de France victories were all based on "one big lie" that involved a scheme of blood doping and taking performance enhancing drugs ("PED"s). Armstrong can now take his place among the great sports liars of our time, Bonds, Clemens, McGuire and all the rest in sports. There are so many.
But Armstrong went further then the rest (even Roger Clemens). To preserve his "one big lie" and financial empire, he sued countless people, newspapers and companies who dared to challenge Armstrong with the truth. Armstrong ruined reputations and actually took millions of dollars in awards based on false defamation suits. He hid behind is cancer charity and used it as a shield against his detractors. For Armstrong to accomplish this feat, he had to take his lying to highest level, perjury.
Now, perjury (or lying under oath crimes) can be difficult to prosecute. Just ask the Justice Department in the criminal case against Roger Clemens. Any lie under oath can be potentially explained by not understanding the question posed or answering a "bad question" with a shady answer.
The problem is that the fundamental principle of our justice system is that the oath to tell the truth is sacred. Think about it, if we allow perjury to be accepted and routine then the entire system has no chance. Everyday, people take the oath to tell the truth and testify in criminal and civil cases. We expect the once under oath, a witness will not lie. We believe that truthful testimony is at the heart of our court system.
Given this fact, every prosecutor (state and federal) in every jurisdiction where Armstrong has given testimony under oath has an affirmative responsibility to investigate a perjury charge. Armstrong cannot be allowed to get away with wholesale lying just because prosecutors are busy with bigger issues and cases.
If we cannot trust the system to demand the truth, then justice has been the biggest victim that Armstrong cheated.