(a) Any person on trial for crime shall be a competent witness, and at his or her option may testify or refuse to testify upon such trial. The neglect or refusal of an accused party to testify shall not be commented upon by the court or prosecuting official, except as provided in subsection (b) of this section.

(b) Unless the accused requests otherwise, the court shall instruct the jury that they may draw no unfavorable inferences from the accused’s failure to testify. In cases tried to the court, no unfavorable inferences shall be drawn by the court from the accused’s silence.