Chris Brown -- I Didn't Confess to the D.C. Assault

Chris Brown did NOT admit he assaulted the alleged victim in his D.C. criminal trial.

Mark Geragos Tells TMZ ... when Brown admitted to a probation violation Friday in the Rihanna case ... it did NOT constitute a confession in his assault case. Geragos says all Brown did was admit he violated probation in D.C. -- he was not more specific.

Geragos tells us ... HE -- not Chris -- conceded there was a factual basis to conclude his client violated probation based on the police report.

What's more, Geragos says there's no way the D.C. prosecutor could use Brown's admission as a confession, because the standard of proof in a criminal case is much higher than in a probation hearing.

Geragos says he merely told the Rihanna judge it's "more likely than not" that Chris screwed up in D.C. In a criminal trial, the prosecutor must show Chris screwed up beyond a reasonable doubt.