Two proceedings, different rules
The new impaired-driving charge proceeds like any other criminal case, with the prosecution required to prove it beyond a reasonable doubt. Separately, the probation department may file a violation in the original case, and in New York that violation is decided under a lower standard of proof at a hearing in the court that imposed probation. The violation can move forward even before the new case is resolved. If the original case was also an impaired-driving matter, the new charge may be elevated as a repeat offense.
Reporting the arrest
Most probation terms require you to report a new arrest to your probation officer within a set time, and failing to do so can be a violation on its own. How you report, and what you say about the facts, is worth discussing with counsel first, because statements to a probation officer are not confidential and can be used. Report the fact of the arrest as required, and avoid discussing details until you have spoken with a lawyer. Keep any written instructions your probation officer gives you. Even if you were held after the arrest and the department already knows, the reporting duty usually still applies.
Planning around both courts
Because the two proceedings affect each other, they need a single plan. A resolution in one may shape what happens in the other, and in some cases they can be resolved together. If your probation includes an ignition interlock or a condition not to drink, those terms will be examined closely. Missing a scheduled probation appointment while the new case is pending adds a separate problem, so keep every one. Bring your probation paperwork, the name of your probation officer, and anything you received at the new arrest. We look at both cases together and explain what each one could mean for your liberty, your license, and your probation term.