## Facts

- Wisconsin’s compulsory attendance law required persons controlling children ages 6–18 to ensure regular attendance at a “public or private school,” and noncompliance was a misdemeanor.
- The statute did not define “private school” and provided no criteria for determining whether an educational program qualified.
- Laurence C. Popanz informed the local school district that his three daughters were withdrawn from public school and enrolled in the “Free Thinker School,” described as a private school administered by a church-related corporation.
- The school district questioned whether the “Free Thinker School” qualified as a private school under the statute.
- Popanz kept his children out of public school based on his view that the Free Thinker School satisfied the law.
- The State charged Popanz with two misdemeanor counts for violating the compulsory attendance statute.

## Issues

1. Whether the term “private school” in the compulsory attendance statute was impermissibly vague.
2. Whether the statute, as applied in prosecutions involving claimed private schooling, violated due process under the Fourteenth Amendment and the parallel provision of the Wisconsin Constitution because it failed to provide adequate notice and enforcement standards.

## Decision

- The Wisconsin Supreme Court reversed Popanz’s convictions.
- The court held that “private school,” as used in the compulsory attendance statute, was impermissibly vague.
- The court held the statute unconstitutional as applied to prosecutions involving private schools.
- The case was remanded with directions to dismiss the criminal complaint.

## Legal Principles

- A criminal statute is void for vagueness if it fails to give a person of ordinary intelligence a reasonable opportunity to know what conduct is required or prohibited.
- A criminal statute must provide sufficiently definite standards to constrain enforcement discretion and prevent arbitrary or discriminatory enforcement.
- Vagueness concerns are heightened when noncompliance carries criminal penalties.
- An undefined compliance category (here, “private school”) that leaves qualification decisions to local officials without legislative standards can violate due process by both inadequate notice and uncontrolled enforcement discretion.

## Conclusion

Because the compulsory attendance statute imposed misdemeanor liability while leaving “private school” undefined and unguided by standards, it did not provide constitutionally adequate notice or enforceable limits on official discretion; Popanz’s convictions were reversed and the complaint ordered dismissed.


State v. Popanz, 332 N.W.2d 750 (Wis. 1983)