The ruling comes in the case of a Colorado man who was stopped in Kansas with medical marijuana he was legally prescribed in his home state.
A Kansas judge acquitted the man of a misdemeanor charge of illegally possessing marijuana.
The state appealed the acquittal, leading to Friday’s ruling that Kansas has the right to enforce its own drug laws even when marijuana was obtained legally elsewhere.
Attorney General Derek Schmidt says the decision doesn’t change the outcome of the Colorado man’s case, and he won’t be tried again. But Schmidt says the ruling will provide guidance to Kansas trial courts in similar cases.