1. Evidence of a written or oral confession, admission, or other statement made by a defendant with respect to his participation or lack of participation in the offense charged, may not be received in evidence against him in a criminal proceeding if such statement was involuntarily made. 2. A confession, admission or other statement is "involuntarily made" by a defendant when it is obtained from him: (a) By any person by the use or threatened use of physical force upon the defendant or another person