Mathematically prove?  Yes, that would be impossible.  I&#x27;m talking legally prove.<p>&gt;prove with clear and convincing evidence<p>Clear and convincing evidence is a set of evidence required to reach the point. It is in-between preponderance of the evidence and beyond a reasonable doubt.<p>Mathematically speaking, no matter how much evidence you have, you can never reach a full proof that someone did some action.  You might get one hundred 9&#x27;s, but you will never get one 100.  But legally, you don&#x27;t need to.  Even the highest standard of evidence does not require a 100% certainty.  But I&#x27;m not even saying we go with the highest, I&#x27;m saying go with clear and convincing.<p>(Clear and convincing is, from what I&#x27;ve seen, the standard needed to award punitive damages resulting from fraud in a civil case.  Preponderance is needed for more exact damages.  Beyond a reasonable doubt is needed for criminal prosecution for fraud.)