In the past, if he was found by the jury to be mute of malice, he would be tortured until he spoke or died (see Peine forte et dure).
In a criminal trial in Oxford Crown Court in 2023, the defendant was a litigant in person who refused to speak in court, whom the jury first found mute of malice, and the following day found guilty of the criminal charge.
[1] The instructing judge said it was the first instance in his 40-year career; that mute of malice meant the defendant "is deliberately faking his inability to speak", and that mute due to visitation of God did not mean that "a deity has descended upon us and struck him down".
[1] In the Netherlands, the concept is not used as in most other countries; the defendant has a constitutional right to silence and a right to refuse self-incrimination under all circumstances, such as in a court hearing or during a police questioning.
The concept is practically foreign to American jurisprudence (it does not even appear in Black's Law Dictionary) because willfully choosing not to speak is a Constitutional right; the defense attorney utters the plea and the defendant does not have to testify (per the case Griffin v. California interpreting the Fifth Amendment to the United States Constitution).