You are probably asking this question because an offer has been made in your case and the resolution seems painful. You don't want to admit to a crime and suffer through imprisonment or probation terms. Perhaps you are concerned about registering as a sex offender and the complications and shame that will follow? What should you do?
Obviously, every case is different so I can't tell you whether a plea is a good idea in your case. What I can do is provide you some general considerations I use when determining whether my client should take a plea deal. It is not a simple decision.
First, you should remember that plea bargains aren't a bad thing. Numbers don't lie. Most cases are resolved by plea. This is typically the best resolution when the offer is balanced correctly. A jury trial carries with it an uncertainty that most people, including prosecutors, cannot tolerate. The main reason a defendant takes a plea deal is to limit risk. Once a plea is accepted, double jeopardy applies, and punishment is locked in. Nothing worse can happen.
Naturally, nothing better can happen either. The downside of a guilty plea is that an acquittal or better deal is forever taken out of the equation. Nevertheless, if the offer is a “bargain”, then agreeing to that resolution makes sense. The real trick is determining whether the offer proposed is actually a "bargain". This requires a dedicated and experienced criminal defense attorney.
In deciding the validity of a plea bargain, the first question a criminal lawyer must answer is WWJD? In other words, what would a jury do? For an accused, a “plea bargain” is a resolution in the case that is substantially better than what a jury or judge would typically dish out. In determining what a jury or judge would do, the criminal lawyer should weigh two things: 1) the strength of the State's case and 2) the background of the accused.
If the State's case is weak and a conviction will be difficult, a “bargain” will likely require a substantial reduction in punishment. If the State's case is so weak that convincing a jury is unlikely, a guilty plea is never a "bargain". (A lawyer who has tried a substantial number of cases will know If evidence is lacking, and whether dismissal is the only acceptable resolution.)
Conversely, if the State's case is strong then a reasonable offer will usually involve greater punishment. In my experience, nothing is more difficult than negotiating with a prosecutor when he has a surveillance video showing the entire criminal event. If a prosecutor knows he can't possibly lose a case, he tends to be hard to convince.
Strength of the case also effects punishment. All things being equal, a jury that is confident in their decision to convict is more likely to be harsh in punishment. A jury that convicts, but harbors residual doubt, often makes up for it in their sentencing evaluation.
The background of the accused matters. If an individual has a criminal background, the jury will hear about it in punishment and sentence accordingly. Prior prison sentences may change the punishment range and take probation off the table. A defendant who has spent time in prison can expect to be sentenced to more time for each subsequent conviction.
If the accused has no criminal record and has developed relationships with solid members of the community, either through family, associations or employment, this can be presented to the jury and will typically weigh in the defendant's favor. Sometimes this information can be presented by the defense in the guilt portion of the trial. (Sometimes this information alone convinces the prosecution to offer less punishment, or even dismissal.)
All of this information must be weighed by the defense attorney in determining what risk his client would be facing in the event of a jury trial. A criminal lawyer with extensive trial experience is best capable of making this assessment. In a vacuum, the decision should be simple. If the offer is not better than what the defense attorney believes the jury or judge is likely to impose, including acquittal, then he should advise his client to proceed to trial. If the offer is better than what he would expect the jury or judge to impose, the offer should be accepted. However, in practice the decision is not so easy.
Human beings are not robots. I have had more than one client who simply could not tolerate pleading guilty, no matter the evidence. Likewise, I have dealt with prosecutors who were blind to the weaknesses in their case. Though they might not have been the best use of judicial resources, jury trials resulted.
In making your decision, you might want to ask a different question. Do you trust your criminal lawyer's experience and dedication? Do you believe he has your best interest at heart? Has he explained to you his reasoning for his advice? Do you trust him? If so, you should take his counsel. You don't want to be asking a different question ten years from now, and wonder why you didn't take your lawyer's advice in the first place.