I believe I am guilty- why do I need a criminal defense lawyer?

A lawyer will be familiar with the possible defenses to your case, which you may not even be aware of.  Additionally, a lawyer can advise you about the consequences of a conviction, such as fines, probation, incarceration, driver’s license suspensions, increased insurance rates, forfeiture of assets, relinquishment of firearm rights, immigration consequences, etc.  There may be options to get charges reduced, or be admitted to a diversionary program to help you avoid being convicted.  A lawyer can help you achieve the best possible result, even if you believe you are responsible for the offense.