But the General Assembly used language that is somewhat awkward when applied to the facts at hand. The phrase in its broadest sense may mean that a person such as J.S. must register even though he never left the county of his residence after the law became effective. This strained interpretation is not consistent with the meaning of the words used. A second reading is that after the law's effective date, any temporary absence from his home county requires J.S. to register within ten days of his return. This interpretation suggests the legislature intended to require registration by one whose work takes him temporarily away from his home county, but not another person who never left home.
Nothing suggests the legislature had that odd purpose in mind.
In discerning the legislature's intent, it is important to consider the context of the whole sentence in which the ambiguous phrase appears. A contextual reading indicates that J.S. correctly discerns the legislative intent. Reading the two phrases together suggests an intent that only a person coming into a county to establish residence must register with the sheriff. This contextual reading is reinforced by the rule of lenity, that is, that ambiguity in a penal statute will be construed against the government or party seeking to exact statutory penalties and in favor of persons on whom such penalties are sought to be imposed. While the requirement of registration is not necessarily punitive, sections 589.400 to 589.425 penalize a failure to register as a class A misdemeanor and subsequent offenses as a class D felony.