The maximum penalty for a 1st offense shoplifting charge is a fine. You cannot be sentenced to jail, even if you have a prior offense, regardless of whether it is still on your record or not, so long as it is not a prior Shoplifting conviction. The larger problem is that if you do not already have a record, this will create one. Often times, it is not the police who catch people shoplifting, it is the loss prevention people at the store who then call the police.
Since the police did not observe the crime and it is a misdemeanor, they have to apply for a criminal application. This sets up a Clerk's Hearing to which you would be summonsed. The Clerk Magistrate hears the police report, read by a police representative, and then allows you or your lawyer to speak in your defense. The Clerk Magistrate then determines if there is sufficient "Probable Cause" to issue a Criminal Complaint. The standard used at this type of hearing is the "Probable Cause" standard, which is far lower than the "Beyond Reasonable Doubt" standard. In fact, if the police report says the store personnel observed you shoplifting, that alone is typically enough for Probable Cause. However, the Clerk Magistrate has discretion at these hearings to decline to issue the complaint if s/he wishes. In many cases if the defendant hires an attorney with some experience in these matters, who knows how to present the defendant in the best light, the Clerk will not issue the complaint.
The key factor appears to be bringing the attorney and the reasoning goes like this: the defendant obviously took this issue seriously enough to hire an attorney. That means they were worried, took it seriously and had to dish out the money for private counsel (as opposed to a public defender which is not available in theses circumstances). The attorney has to be wise enough or experienced enough to know how to represent the defendant and to be amicable and not confrontational since in most cases the defendant was caught red handed and/or confessed their guilt. It is also important to have an attorney just in case the complaint does issue. It is one thing for an attorney to dance around an admission without coming right out and admitting guilt where a defendant on his/her own will be admitting guilt on the record if s/he speaks for him or herself.
That admission could be used later at the criminal level if the complaint did issue whereas what the attorney says is not testimony but argument. The simple advice is if you care about the outcome and want the very best chance of keeping this off of your record bring an attorney and make sure they have experience with these type of matters. Good luck!