How have the courts interpreted the Miranda rights of a defendant in a civil case?

Prior to the jury trial, Porteous moved to exclude from the guilt phase of the trial evidence of her post-arrest statement to a police detective on grounds that it was obtained in violation of Miranda v. Arizona, 384 U.S. 436 (1966). The court conducted an evidentiary hearing on the issues of whether Porteous' waiver of her Miranda rights was knowing and intelligent and whether the statement that followed was voluntary. After hearing argument from both parties, the court ruled that the waiver was knowing and intelligent and the statement was voluntary. It consequently denied Porteous' motion.