Kaupp V. Texas

This case turns on the Fourth Amendment rule that a confession "obtained by exploitation of an illegal arrest" may not be used against a criminal defendant. Brown v. Illinois, 422 U. S. 590, 603 (1975). After a 14-year-old girl disappeared in January 1999, the Harris County Sheriff's Department learned she had had a sexual relationship with her 19-year-old half brother, who had been in the company of petitioner Robert Kaupp, then 17 years old, on the day of the girl's disappearance. On January 26th, deputy sheriffs questioned the brother and Kaupp at headquarters; Kaupp was cooperative and was permitted to leave, but the brother failed a polygraph examination (his third such failure). Eventually he confessed that he had fatally stabbed his half sister and placed her body in a drainage ditch. He implicated Kaupp in the crime.