Answer: polygraph

AnswerCrossword Clue
POLYGRAPHStoryteller?
POLYGRAPHDetective's device
polygraphA lie-detector test carried out with a machine of this type
polygraphA machine designed to detect and record changes in physiological characteristics, such as a person's pulse and breathing rates, used esp. as a lie detector
polygraphan instrument for multiplying copies of a writing / to copy by polygraph