This chapter provides an overview of suspect interview and interrogation procedures, with a focus on those with mental illness, neurodevelopmental disorders, and juveniles. Some individuals lack the cognitive ability to understand their rights and are more likely to provide police with false or misleading statements. Many disabilities and mental illnesses are “hidden,” and police may not be aware of suspects’ cognitive, social, or communication limitations. This chapter covers the underlying principles and cautions when questioning and interrogating suspects, including comprehension of Miranda warnings, suggestibility, and other risks associated with providing false confessions. To ensure police receive accurate information, the chapter concludes with considerations and recommendations from experts in the field when questioning suspects with mental illness, neurodevelopmental disorders, and juveniles.