Suspended Imposition of Sentence is a Missouri-specific option where the defendant pleads or is found guilty, but the court suspends actually imposing a sentence. Instead, the defendant goes on probation. If probation is successfully completed, no conviction appears on the public record.
SIS is highly desirable for first-time offenders, especially professionals or anyone whose employment depends on a clean record. It's not available for every charge. DWI second offenses, certain felonies, and other specified offenses are excluded.
SIS doesn't make the case disappear. The record exists on the closed file accessible to courts, certain employers, and law enforcement. Some applications and licenses still require disclosure. But for most purposes (background checks, employment applications, professional licensing) the absence of a conviction makes a meaningful difference.