Would this really be much of a deterrent when there is so much looking the other way in police ranks? If someone were in good with the police chief I would think they wouldn't really care what goes on their record, especially if they aren't officially reprimanded. In fact, I would guess some police chiefs would commend such an officer as doing their job thoroughly.
As you probably know, the US Supreme Court has ruled that it is sometimes necessary for investigating police officers to lie about what has happened (except under oath) in order to further their investigation concerning a crime they believe may have occurred.
Police may legally lie during the course of their jobs if they think it will help facilitate an investigation and/or interrogation. However they cannot legally lie under oath - which covers both courtroom testimony and most depositions.
In answer to your posed question, yes - it would serve as a deterrent if citizens more actively forced cops to account under oath for all of their actions.
If you are facing criminal charges, you have the legal right to requisition the complete personnel records of any cops involved in the case. A cop being challenged on the legitimacy of a search - for example - would face increased pressure if he had a history of such challenges being brought against him. This pressure increases of course if one or more of the cases in his history has been ruled against him.
Within the context of our immediate discussion here, if I were charged with DC and felt the charge to be without merit, I would immediately demand the personnel record of the arresting officer(s). I would have them testify under oath as to how many times they had arrested people on this charge. I would have them testify as to what percentage of these arrests were ultimately prosecuted. I would have them testify as to how many of those prosecutions returned convictions.
Any way I could create a reasonable doubt in the mind of the jury as to the legitimacy of this officer's judgement in the Job is to my advantage. And it also helps plant seeds for future defendants who might face similar arrest charges from these same officer(s).