Peter Gregory Cain v. the People of the State of Colorado

Summary

The court held that preliminary breath test results may be used only in the statutory probable-cause hearing and may not be introduced at trial for impeachment or any other purpose. The county court therefore impermissibly burdened Cain's constitutional right to testify by conditioning his testimony on admission of the otherwise inadmissible result, and the error was not harmless beyond a reasonable doubt. The court reversed and remanded for a new trial. No separate opinions were filed.