I cannot formally advise you on your particular matter, since I am not your attorney and have not fully investigated the facts. I would encourage you to retain an attorney. But I can tell you that most courts have a rule that generally requires a witness to be present in court for the testimony of that witness to be in evidence. For example, if a police officer observed a driver swerving across the road and then staggering when the driver exited the vehicle, the prosecutor can only use that evidence against the defendant if the officer testifies in court. This is known as the hearsay rule. There are many subtleties to this rule and many exceptions, which vary considerably depending on the jurisdiction. Also, a prosecutor has the burden of proving his case against the defendant, and if he cannot meet that burden then the case usually just gets dismissed.
Of course, every case is different and my comments are just general and not about your particular case. If you require advice about your specific case, then I would encourage you to hire an attorney.
Best of luck.
The officer does not have to attend non-trial settings, and generally does not. If the case is set on the trial docket, the prosecutor will subpoena the officer. The prosecution will need, at a minimum, a person who can place you behind the wheel of the car driving at a time when you were impaired - so a wheel witness and a witness as to intoxication (who can be the same witness). It is not likely that the witness simply will not show up, and if the witness does not show, the prosecutor can move to have him attached and brought to court.
There are certain occasions where the officers, or any witness, must be in court such as trial or certain evidentiary hearings. There are many dates where they are not required to appear.
If you are arrested or charged, you should contact a lawyer immediately. In fact, you may wish to contact a local lawyer to review the case with you and to search the court records for charges.
The role that the officer would play in any trial against you is to provide evidence that you were inebriated and that he had probable cause for pulling you over to begin with. For example, the officer might testify that you were weaving in and out of your lane, giving him reason to pull you over in the first place. Secondly, the officer might testify that you failed the field sobriety tests. If he is not present in court this testimony cannot be placed into evidence. Your BAC, however, can. You can always try to challenge the probable cause for pulling you over to begin with.
Sign up to receive a 3-part series of useful information and legal advice about DUIs.