¶ 1. Defendant, Robert V. Horn (Horn) challenged the constitutionality of Wis. Stat. § 973.10(2) requiring administrative, *640 rather than judicial, revocation of probation. The circuit court agreed with Horn and declared the statute unconstitutional as a violation of the separation of powers doctrine. The issue presented by this case is whether it is within the exclusive power of the judiciary to determine whether a defendant has violated the court-imposed conditions of probation and whether probation should be revoked and the defendant sent to prison. We conclude that disposition of a criminal case, including imposing and revoking probation, is within powers shared among the branches of government. Because the legislative delegation of probation revocation to the executive branch does not unduly burden or substantially interfere with the judiciary's constitutional function to impose criminal penalties, we determine that § 973.10(2) is constitutional. Accordingly, we reverse the order of the circuit court.
¶ 2. The facts for purposes of this appeal are limited and not in dispute. Horn pleaded guilty to two felony counts of delivery of cocaine, contrary to Wis. Stat. §§ 161.16(2)(b)1 and 161.41(1)(cm) (1992-93). 1 The Kenosha County Circuit Court, the Honorable Bruce E. Schroeder presiding, adjudged Horn guilty and ordered a presentence investigation report. On March 9, 1995, the circuit court withheld Horn's sentence, placed him on probation for four years, and ordered him to pay restitution.
¶ 3. In July 1997, the Wisconsin Department of Corrections initiated probation revocation proceedings against Horn, pursuant to Wis. Stat. § 973.10(2) *641 (1995-96). 2 The Department of Corrections asserted that Horn violated several conditions of his probation. He also faced new charges of obstructing as a repeater and stalking as a repeater. On August 14, 1997, Horn filed a motion with the circuit court, requesting that the court determine § 973.10(2) unconstitutional as violating the separation of powers doctrine. Horn served this motion on the Attorney General, pursuant to Wis. Stat. § 806.04(11), who filed a response in opposition to the motion.
¶ 4. The circuit court granted Horn's motion and declared Wis. Stat. § 973.10(2) unconstitutional concluding it violates the separation of powers doctrine. The circuit court determined that the statute imper-missibly infringes on the judiciary's exclusive sentencing function. Accordingly, the circuit court enjoined the Department of Corrections from further proceedings with the probation revocation process and set a date for a probation revocation hearing before the circuit court.
¶ 5. The circuit court based its decision on its conclusion that probation is a stay in an ongoing criminal proceeding. The circuit court determined that not only does probation stay execution of a sentence, see Wis. Stat. § 973.09(1)(a), but the circuit court continues to have power to modify the terms of probation, see § 973.09(3)(a). The circuit court concluded that Wis. Stat. §973.10(2), requiring administrative probation revocation, allows the executive branch to administratively lift the judicially-imposed stay, and violates the separation of powers doctrine in that only a court should be able to lift a judicially-imposed stay.
*642 ¶ 6. The State of Wisconsin (State) petitioned the court of appeals for leave to appeal a nonfinal order. The court of appeals granted the State's petition. After hearing oral arguments, the court of appeals certified the case to this court pursuant to Wis. Stat. § (Rule) 809.61, which we accepted.
¶ 7. The issue presented by this case and as certified by the court of appeals is whether it is within the exclusive power of the judiciary to determine whether a defendant has violated the court-imposed conditions of probation and whether probation should be revoked and the defendant sent to prison. In other words, we must determine whether Wis. Stat. § 973.10(2) (reprinted below),
3
which provides for administrative revocation of probation, unconstitutionally violates the separation of powers doctrine. Whether a statute is constitutional is a question of law which this court reviews de novo.
State v. Borrell,
*643
¶ 8. When a party challenges the constitutionality of a statute, we begin with the presumption that the statute is constitutional.
St. ex rel. Friedrich v. Dane County Cir. Ct.,
¶ 9. This court has frequently expounded the separation of powers doctrine. "The doctrine of separation of powers, while not explicitly set forth in the Wisconsin constitution, is implicit in the division of governmental powers among the judicial, legislative and executive branches."
Friedrich,
¶ 10. The constitutional powers of each branch of government fall into two categories: exclusive powers and shared powers. Each branch has exclusive core constitutional powers into which other branches may not intrude.
Friedrich,
¶ 11. Shared powers lie at the intersections of these exclusive core constitutional powers. These " '[gjreat borderlands of power'" are not exclusive to any one branch.
Friedrich,
¶ 12. In the present case, Horn argues that Wis. Stat. § 973.10(2), requiring administrative revocation of probation, impermissibly intrudes upon the judiciary's constitutional power to sentence criminal defendants. To determine whether legislation unconstitutionally intrudes upon judicial power and therefore violates the separation of powers doctrine, this court developed a three-part test.
Flynn,
¶ 13. If the subject matter of the statute is within the powers constitutionally granted to the judiciary and the legislature, the statute is within an area of shared powers.
Flynn,
¶ 14. We now apply this separation of powers analysis to the facts presented by this case. In regard to sentencing in general, we can easily dispense with the first two inquiries — whether the subject matter is within powers constitutionally granted to the legislature and the powers constitutionally granted to the judiciary.
¶ 15. It is settled that sentencing in Wisconsin is an area of shared powers.
Borrell,
¶ 16. The legislature has authority to determine the scope of the sentencing court's discretion. The sentencing court has discretion, within that legislatively-determined scope, to fashion a sentence based on the nature of the criminal offense, the need to protect the public and the need to rehabilitate the defendant.
Borrell,
The fashioning of a criminal disposition is not an exercise of broad, inherent court powers. It is for the legislature to prescribe the punishment for a particular crime and it is the duty of the court to impose that punishment; if the authority to fashion a particular criminal disposition exists, it must derive from the statutes.
State v. Amato,
¶ 17. Although case law makes clear that sentencing is within shared powers, we must determine *647 whether probation and probation revocation are also within shared powers. The first inquiry is whether probation and probation revocation are within powers constitutionally granted to the legislature.
¶ 18. Probation itself is generally not a sentence.
Prue v. State,
¶ 19. The second inquiry in the separation of powers analysis is whether probation and probation revocation are within powers constitutionally granted to the judiciary. Again, the question is easily answered. Although probation is not a sentence, it is a possible disposition for criminal defendants, and therefore, probation falls within the judiciary's power to impose a
*648
penalty.
See Drinkwater,
¶ 20. We determine, consistent with sentencing and probation as an alternative to sentencing, that probation and probation revocation are within shared powers. Like sentencing, the legislature has constitutional authority to offer probation as an alternative to sentencing, the judiciary has authority to impose probation, and the executive branch has the authority to administer probation.
¶ 21. Having concluded that both sentencing and probation are within shared powers, we turn to the third inquiry of the separation of powers analysis — whether the subject matter of Wis. Stat. § 973.10(2), requiring administrative probation revocation, unduly burdens or substantially interferes with the judiciary's function to impose criminal penalties.
¶ 22. The legislature's grant of authority to impose probation provides that unless probation is statutorily prohibited for a particular offense, "if a person is convicted of a crime, the court, by order, may withhold sentence or impose sentence under s. 973.15
*649
and stay its execution, and in either case place the person on probation to the department [of corrections] for a stated period. . . Wis. Stat. § 973.09(1)(a). Also, according to statute, if the executive branch revokes the defendant's probation, the probationer is brought before the court for sentencing if the sentence was withheld, or, if the probationer was sentenced but the sentence stayed, the probationer is sent to prison to serve the sentence. Wis. Stat. § 973.10(2)(a) and (b). "The sentence [the defendant] is required to serve upon revocation is the punishment for the crime of which he [or she] has previously been convicted."
State ex rel. Flowers v. H&SS Department,
¶ 23. When a circuit court imposes probation and sentences a defendant, whether a sentence is imposed and stayed, or withheld, the circuit court fully exercises its constitutional function to impose a criminal disposition. If a circuit court imposes a sentence but stays its execution and places the defendant on probation, the circuit court fully exercises its discretion and constitutional function in determining the sentence within the statutory guidelines provided for the offense and in placing the defendant on probation pursuant to Wis. Stat. § 973.09(1)(a). If a circuit court withholds sentence and places the defendant on probation, the circuit court exercises its discretion and constitutional function in ordering such disposition and, if necessary, will later exercise its discretion in imposing a sentence after probation has been revoked. Probation revocation does not unduly burden or substantially interfere with *650 the judiciary's constitutional function to impose criminal penalties.
¶ 24. Horn argues that probation is a stay in an ongoing criminal proceeding and that allowing administrative revocation of probation allows the executive branch to intrude in an ongoing criminal proceeding which is the province of the judiciary. We disagree. The plain language of the statute regarding imposing probation provides that a court may "withhold sentence or impose sentence. . .and stay its execution. ..." Wis. Stat. § 973.09(1)(a). This language provides that a sentence imposed, not the criminal proceeding, is stayed by probation.
¶ 25. In fact, the criminal proceeding cannot be stayed because once a defendant has been charged with a crime, tried, defended, convicted, sentenced, and gone through an appeal if desired, the litigation is over and the judicial process has ended.
Johnson,
¶ 26. Although a court has statutory authority to extend probation or modify the terms of a defendant's probation up until the time probation expires, Wis. Stat. § 973.09(3)(a), allowing the executive branch to determine whether a defendant has violated the conditions of his or her probation to such a degree as to warrant revocation does not unduly burden or substantially interfere with either the judiciary's constitutional function to impose criminal penalties or its statutory authority to extend probation or modify its terms prior to the expiration of probation. The judiciary still has authority to sentence the convicted defendant to prison or to impose probation and withhold or stay sentencing.
¶ 27. Defendant attempts to make an analogy between a court's powers regarding probation and powers regarding contempt. While "the power of a court to hold a person in contempt is an inherent power of the court. . .the legislature may subject the power to reasonable regulation, [but] it may not withdraw the power."
Smith v. Burns,
¶ 28. Horn also argues that the judiciary lacks meaningful review of an administrative revocation of probation. We disagree. Certiorari is a meaningful review. Judicial review of an administrative decision is by writ of certiorari, reviewing the agency's decision, not that of the circuit court.
State ex rel. Warren v. Schwarz,
¶ 29. Horn finally argues that it is striking that Wisconsin is the only state that requires administrative rather than judicial probation revocation. First, we note that we analyze Wis. Stat. § 973.10(2) using a separation of powers analysis based on the Wisconsin Constitution. How this analysis might play out in other jurisdictions based on other state constitutions is of no consequence. Additionally, "[njothing in the federal Constitution forbids a state from providing for administrative revocation of probation imposed by a court."
Ware v. Gagnon,
*653
¶ 30. The United States Supreme Court determined that due process requires that a person subject to parole revocation be afforded a hearing before a "neutral and detached" hearing officer at both the preliminary hearing and at the final revocation hearing.
Morrissey v. Brewer,
¶ 31. In sum, we hold that administrative revocation of probation, as provided in Wis. Stat. § 973.10(2), falls within an area of shared powers. Horn has failed to show beyond a reasonable doubt that the legislative delegation of probation revocation to the executive branch unduly burdens or substantially interferes with the judiciary's constitutional function to impose criminal penalties. The judiciary retains authority to impose a sentence on the convicted defendant or to impose probation and withhold or stay a sentence. Therefore, § 973.10(2) is constitutional. Accordingly, we reverse the order of the circuit court.
By the Court. — The order of the circuit court is reversed.
Notes
Wisconsin Stat. §§ 161.16(2)(b)1 and 161.41(1)(cm) (1992-93) were renumbered as Wis. Stat. §§ 961.16(2)(b)1 and 961.41(1)(cm) (1995-96). 1995 Wis. Act 448, §§ 168-171, 173.
All references to the Wisconsin Statutes are to the 1995-96 version unless otherwise indicated.
Wisconsin Stat. § 973.10(2) provides:
(2) If a probationer violates the conditions of probation, the department of corrections may initiate a proceeding before the division of hearings and appeals in the department of administration. Unless waived by the probationer, a hearing examiner for the division shall conduct an administrative hearing and enter an order either revoking or not revoking probation. Upon request of either party, the administrator of the division shall review the order. If the probationer waives the final administrative hearing, the secretary of corrections shall enter an order either revoking or not revoking probation. If probation is revoked, the department shall:
(a) If the probationer has not already been sentenced, order the probationer brought before the court for sentence which shall then be imposed without further stay under s. 973.15; or
(b) If the probationer has already been sentenced, order the probationer to prison, and the term of the sentence shall begin on the date the probationer enters the prison.
