Rule 1153.5 Evidence of an offer for civil resolution of a criminal matter pursuant to the provisions of Section 33 of the Code of Civil Procedure, or admissions …

If someone accused of a crime offers to settle the matter civilly (by paying money instead of going through criminal court), that offer cannot be used against them in any court case.

This also covers anything said during the back-and-forth negotiating process. So if you make statements or admissions while trying to work out a civil settlement for a criminal matter, those words cannot be brought up later in court to hurt your case.