Do I need a lawyer for first offense possession of 3 grams of marijuana?

Whether you "need" a lawyer is a question a person must answer for themselves.  But as a general rule even a first offense for marijuana possession is an offense for which you have a right to a lawyer.  The first question in any criminal case is whether or not the government can prove the offense beyond a reasonable doubt.  A lawyer can certainly assist a person charged in finding out the evidence and ultimately expressing an opinion as to whether or not that evidence will likely be sufficient to convict.  The second question is, if the evidence is sufficient, what will the likely penalty be.  The range of penalty for a true first offense in Virginia can include up to 30 days in jail.  Under some circumstances a first offense can also be taken under advisement for a period of time and dismissed even when the evidence is sufficient.  Where any individual case may fall in that spectrum is something a lawyer can give an informed opinion on and also help to achieve the best result that the evidence and law allow.  Whether or not you wish to hire (or perhaps qualify for a court appointed attorney) however, is a choice each individual client must make.  Since the charge of first offense marijuana possession is a criminal misdemeanor, I tend to recommend that anyone charged with that have legal counsel.