Conrad Murray's Mom She Doesn't Know Jack (Daniels) About Her Son

11/30/2011 5:30 AM PST

Conrad Murray's Mom Didn't Know Jack (Daniels) About Her Son

Note to Conrad Murray's mom.  You were wrong when you told Judge Michael Pastor your son never had a drink in his life, and we have the proof -- 80 proof.

Murray's mom wrote a letter to Judge Michael Pastor before his sentencing, pleading for mercy for her son and claiming Conrad is a good person who "never drank alcohol, took drugs or smoked cigarettes in his life."

But here's the deal.  We got this pic of the Doc, who was at a holiday bash in Vegas in the late '90's.   You see Murray triple fisting.  People at the party tell us Murray was drinking champagne and cocktails all night long.

At least he won't get extra jail time for this lie.

UPDATE:  Although witnesses at the party say Murray was drinking, a source connected with the Doc tells TMZ ... Murray was handing out glasses of champagne, and the cup he's holding is filled with soda.