The trial court erred when it dismissed a special circumstance pursuant to Penal Code section 190.2, subdivision (a)(10), which alleged that the victim, who was a witness to a crime, was killed in retaliation for testifying. The victim was an inmate who was stabbed to death. He had testified for the prosecution, but did not claim to be a witness to the murder, and denied any involvement or knowledge. The prosecutor argued that although the testimony was “innocuous” the witness-killing special circumstance applied because the victim had testified at the trial. The magistrate dismissed the special circumstance, stating that the statute required that there must be some testimony that would in some way implicate the person on trial, which it did not find. The Court of Appeal reversed the trial court’s ruling. Nothing in the statute supports the trial court’s conclusion that the killing must be in retaliation for what was said rather than for the mere act of testifying. The content of the victim’s testimony is not an element of the special circumstance. All that is required is that the defendant killed the victim in retaliation for the act of testifying in a criminal proceeding, for which substantial evidence existed here.