* * *" In State v. Sheriff of Pima County, 97 Ariz. 42, 396 P.2d 613, we said: "The State of Arizona sought a writ of habeas corpus ad prosequendum in this Court to direct the Sheriff of Pima County and the Supervisor of the Arizona State Hospital, to release and transport Peter Damskey to the Justice of the Peace Court in Pima County for a preliminary examination on the charges of murder and assault with intent to commit murder pending before that Justice of the Peace Court. That writ was granted by this Court on October 6, 1964.

In State v. Buchanan, 94 Ariz. 100, 381 P.2d 954 we held that a defendant can be criminally tried and sentenced if he can understand the nature of the proceedings against him and assist in his defense though he has been certified as incompetent and committed for the treatment of a mental illness. See also State v. Sheriff of Pima County, 97 Ariz. 42, 396 P.2d 613. Defendant's final argument is that the verdicts are contrary to the evidence.

There was no error in denial of petitioner's motion. State v. Heisler, supra; State v. Kostura, 98 Ariz. 186, 403 P.2d 283; cf. State v. Sheriff of Pima County, 97 Ariz. 42, 396 P.2d 613. Petitioner next contends that he was deprived of a fundamental right to be informed of the charges against him. During the eighteen-month period between filing of the complaint and his release from the Arizona state prison, petitioner argues he did not know when the robberies were alleged to have been committed, who the victims were, or where the robberies allegedly took place.

And it may be used to transfer a person from a state facility to a county jail. See State v. Sheriff of Pima County, 97 Ariz. 42, 43, 396 P.2d 613, 613–14 (1964). Thus, Seay was in the custody of Cochise County when transferred pursuant to that writ, and he clearly was in custody for the offenses charged in the October 6 indictment. See§ 13–712(B); De Passquallo, 140 Ariz. at 229, 681 P.2d at 381.

It is generally true that the state may use a writ of habeas corpus ad prosequendum to return the accused to the county where charges have been filed. State v. Sheriff of Pima County, 97 Ariz. 42, 43, 396 P.2d 613, 614 (1964); cf. United States v. Mauro, 436 U.S. 340, 355-56, 98 S.Ct. 1834, 1845, 56 L.Ed.2d 329 (1978). A defendant has a Sixth Amendment right to a speedy trial on charges pending in one state while he is incarcerated in another; that writ is a proper method of bringing a defendant to trial.

We conceive that the simultaneous suspension of criminal prosecution was intended to safeguard petitioner's interests since a finding of civil incompetency does not serve to avoid criminal prosecution. State v. Sheriff of Pima County, 97 Ariz. 42, 396 P.2d 613 (1964); State v. Buchanan, 94 Ariz. 100, 381 P.2d 954 (1963); McWilliams v. Justice Court, Tucson Precinct No. 1, 5 Ariz. App. 200, 424 P.2d 848 (1967). As to petitioner's double jeopardy argument, there is substantial authority that the constitutional ban against double jeopardy prevents prosecution in the adult court for the same offense upon which an adjudication of delinquency was predicated.

A finding of civil incompetency does not preclude criminal prosecution. State v. Buchanan, 94 Ariz. 100, 102, 381 P.2d 954 (1963); State v. Sheriff of Pima County, 97 Ariz. 42, 43, 396 P.2d 613 (1964). As pointed out in State ex rel. Ronan v. Stevens, 92 Ariz. 227, 375 P.2d 717 (1962), there are different degrees of mental incompetency and a "mentally ill person" as defined in A.R.S. § 36-501(2) may be competent to the extent that "he is [able] to understand the proceedings against him and to assist in his defense."