The Williamson rule is that a defendant cannot be convicted of a general statute when a more specific statute applies. For example, stealing from a store could be charged as shoplifting and as theft. Shoplifting though is the more specific crime because it specifically involves taking something from a store, whereas theft could be taking from a store or taking from other places. So if a person took property from a store, they could only be charged with shoplifting and not theft.
Sometimes this rule can change a person’s life. In a recent case, People v. Henry (2018) 28 Cal.App.5th 786, the defendant gave a false name during a traffic stop. Giving a false name whenever you’re about to receive any kind of penalty is a violation of Penal Code section 529, false impersonation, which can be a felony. But giving a false name specifically during a traffic stop is a violation of Vehicle Code section 40504(b), which is a misdemeanor.
In this case, the defendant was charged with felony false impersonation and was sentenced to seven years prison after his trial. However, the appellate court reversed his conviction and held that under the Williamson rule, the defendant could not be convicted of the general crime (Penal Code 529) if a more specific crime (Vehicle Code 40504) applied.
That means this person’s sentence would be reduced from seven years prison to a maximum of six months jail!