Deaf People, especially those who are not well educated, are at risk for serious injustices when they enter the criminal justice system. The present study describes these risks at all stages of the legal process, including arrest, trial, probation, prison, and parole. These dangers are greatest for those who are poorly educated, read at a fourth-grade level or lower, have poor communication skills (American Sign Language and English), and lack awareness of their legal rights. "Primitive personality disorder" (PPD) is the term mental health professionals use to describe this set of characteristics. The risks that the segment of the deaf population with PPD faces when its members run afoul of the law are described, a case history provided, and some relevant legal and interpreting issues are discussed. A case is made for applying the concept of linguistic incompetence to deaf individuals with PPD. (Contains 3 tables.)