I'm often asked by my criminal defence clients: "should I plead guilty? What you do think I should do?" Unfortunately, these are such personal decisions, potentially have such great ramifications for my clients' lives, that I unfortunately can't give them direct answers to those kinds of questions.
The best I can do is explain to them: (1) all of their options (sometimes there are more options than simply plead or don't plead), (2) the likely consequences of their options, and (3) that usually they don't have to make an instantaneous decision about pleading. They can take a few days or weeks to talk it over with friends and family, and ask me follow up questions. The last thing I want for any of my clients is for them to later regret whatever decisions they arrive at.
There are five primary factors I tell my clients to consider when deciding whether or not to plead.
1. Did you actually commit a criminal act? For clients who are completely innocent of any wrong doing, I can't ethically help them plead guilty to things they didn't do. Even though they might be offered good plea "deals" and even though those deals would get their matters out of the way so that they could move on with lives. I (and other criminal defence lawyers) just can't do that. But there's some nuance to this question. Even if you didn't do exactly what is alleged factually or legally against you, you might have still committed a criminal offence, and so you might still be able to properly plead to something.
2. Can you live with the likely consequences of a guilty plea? If the consequence of a plea will be a criminal record, and you absolutely can't live with that - perhaps because it would ruin your career - then you probably won't want to plead. Likewise if there will be a consequence like a two year driving suspension that you can't live with, again you'll want to think twice before pleading. But if the consequences won't ruin your life - maybe you'll be getting a discharge that avoids a criminal record, or receive a fine that avoids jail - that a plea might be a good idea.
3. Can you financially and emotionally afford to go to trial? The answer to this question might depend on the kind of charges you are facing. Going to trial on an impaired driving charge might only cost you a few thousand dollars in legal fees, and the time waiting for a trial date could be under a year. However, going to trial on a drug conspiracy might involved tens of thousands of dollars in legal fees, and many years of legal proceedings as the case drags through first a preliminary inquiry and then possibly a multi-week trial. Some of my clients just "want to get it over with" and move on with their lives. Whereas others are willing to be patient, and spend a year or more waiting to see how things play out.
4. Is the sentence after trial likely to be much worse than the sentence on a plea? The rule of thumb is that a guilty plea will save you about 1/3 off your sentence. But sometimes it may be a lot more of less. Like the difference between getting a criminal record, and not getting a criminal record. Thus you and your lawyer will need to carefully evaluate the "bad outcome" risk of going to trial. If the Crown is seeking two years imprisonment on a plea, and the worst case scenario after trial might be 2 1/2 years, then that isn't a lot of risk to take. But if the Crown will take a fine on a plea, and will want three months in jail after trial, then that is a huge difference.
5. What are you chances of winning a trial? This is a question to which your lawyer won't be able to give you precise odds, but she or he should be able to tell you in general terms whether you have a defence to present. Sometimes the defence might be very "technical" (like that an officer wasn't properly qualified to administer a particular test), sometimes it might be based on a violation of your "rights" (like that there was no legal power to search you car), and at other time it could simply be based on your testimony needing to be believed at trial that you "didn't do it." Your lawyer should be able to tell you if you have good or bad chances at trial, based on the evidence the Crown plans to present against you, and the legal defences you'll be able to raise.
For any of the considerations, the key point to remember is that you should get some legal advice prior to making the decision to plead or not plead. That advice might be from your own privately retained lawyer, from a lawyer paid by legal aid, or from duty counsel in the courthouse. Where you get the advice is less important than the fact that you need such advice prior to pleading or setting a trial date.