You voluntarily and spontaneously inform your probation officer about new charges. If your probation officer asks about you, you should tell him. Your probation officer will call you or invite you to come down to her office on a frequent basis. They are informed by technology. If you are on probation in a specific city or state and are arrested/charged in the same court/jurisdiction as before, your probation officer will very certainly receive an alert. Searches on a regular basis When you have a defendant’s entire name and date of birth, searching databases is simple (and social security number). People interact with one another. The law enforcement community is quite small. You may not realize it, but police officers (and prosecutors) frequently discuss their cases with one another.