OPINION BY
John T. Oliver and Ralph E. Unis, Jr. (Appellants) appeal from an order of the Court of Common Pleas of Butler County (trial court) vacating their summary convictions under the Solid Waste Management Act (Act)1 and ordering Appellants held over for trial. In doing so, the trial court granted the Commonwealth’s petition for certiorari review of an adjudication by a district justice.2 Appellants contend that the trial court’s action violated their constitutional right not to be placed in double jeopardy.
In 1998, the Department of Environmental Protection (DEP) investigated complaints of large fires burning at night on property owned by Oliver in Donegal Township, Butler County (Property). DEP referred the matter to the Attorney General for possible criminal prosecution based upon allegations by several witnesses that construction and demolition waste had been dumped and burned on the Property. A state-wide investigating grand jury issued a presentment recommending criminal charges against Appellants; the presentment was accepted by the Supervising Judge on September 25, 2003. Reproduced Record at 30-38 (R.R. -).3 As a result, the Commonwealth filed identical criminal complaints against Appellants, charging each of them with violating Sections 610(2), 610(3) and 610(6) of the Act.4 The Commonwealth listed each *1169of the aforementioned charges as a misdemeanor of the third degree.
Appellants proceeded to a preliminary hearing before District Justice Joseph D. O’Donnell (District Justice) on February 11, 2004. Evidence was presented that Oliver had admitted to an investigating agent of the Attorney General’s Office that he had authorized Unis to dump construction and demolition waste on the Property to be burned. Oliver also stated that these waste materials came from a budding he owned in the City of Butler that was being demolished by Unis. Additionally, Timothy Switzer, Oliver’s tenant on the Property, testified that he agreed with Oliver to burn the materials dumped by Unis in exchange for “some beer and cigarettes and that.” Notes of Testimony 2/11/04 at 31 (N.T.-); R.R. 150. Neither Oliver nor Unis, nor any person or entity affiliated with the Property has ever been granted a permit from DEP to conduct such activities.
At the conclusion of the Commonwealth’s case, Appellants questioned the propriety of the Commonwealth charging them with third-degree misdemeanors and requested that the District Justice “take jurisdiction” of the charges against them as summary offenses. Id. at 54-55; R.R. 173-174. The Commonwealth opposed Appellants’ motion and reiterated that Appellants had been charged with misdemeanors of the third degree for “a continuing course of conduct in violation of the law.” Id. at 55; R.R. 174. After a brief recess, the District Justice found Oliver and Unis each guilty of one summary offense under the Act and sentenced them to pay fines of $300 plus costs.5
The Commonwealth petitioned the trial court to issue a writ of certiorari to review the District Justice’s verdicts against each of the Appellants. Alternatively, the Commonwealth filed a notice of appeal from the District Justice’s decision. Appellants answered the petitions and moved to strike the notices of appeal. Following oral argument, the trial court issued the writs of ceHiorari on July 9, 2004. The trial court vacated the District Justice’s verdicts and, based upon its own review of the evidence offered at the preliminary hearing, found that the Commonwealth had established its prima facie case against Oliver and Unis. Accordingly, the court ordered Appellants held over for trial on the original misdemeanor charges. Appellants’ timely appeal to this Court followed.6
*1170On appeal, Appellants contend that the Double Jeopardy Clauses of the United States and Pennsylvania Constitutions7 prohibited the trial court from exercising the functional equivalent of appellate jurisdiction, whether by issuance of a writ of certiorari or otherwise. In Appellants’ view, the Commonwealth is attempting to retry them on misdemeanor violations after they were convicted by the District Justice of summary offenses containing identical elements. The Commonwealth counters that the proceedings before the District Justice were a legal nullity because he lacked jurisdiction to transform the preliminary hearing into a summary trial. Thus, the Commonwealth contends, jeopardy never attached. We agree.
We begin with Section 606 of the Act (Criminal penalties), which provides, in pertinent part, as follows:
(a) Any person, other than a municipal official exercising his official duties, or any municipality who violates any provision of this act, ... upon conviction thereof in a summary proceeding, shall be sentenced to pay a fine of not less than $100 and not more than $1,000 and costs and, in default of the payment of such fine and costs, to undergo imprisonment for not more than 30 days.
(b) Any person other than a municipal official exercising his official duties who violates any provision of this act, ... shall be guilty of a misdemeanor of the third degree and, upon conviction, shall be sentenced to pay a fine of not less than $1,000 but not more than $25,000 per day for each violation or to imprisonment for a period of not more than one year, or both.
35 P.S. § 6018.606. Our Supreme Court has reviewed this statutory language and held that “the decision of whether to prosecute an alleged offender under sections 606(a) or 606(b) is a matter legitimately committed to the sound discretion of the prosecutor or agency charged with enforcement of the Act.” Commonwealth v. Parker White Metal Company, 512 Pa. 74, 95, 515 A.2d 1358, 1369 (1986). Thus, the Act unquestionably vests discretion in the Commonwealth to charge a violation as either a misdemeanor or summary offense.
The Pennsylvania Rules of Criminal Procedure recognize the fundamental distinction between misdemeanor and summary offenses. At the outset, Rule 103 instructs that a misdemeanor offense shall be adjudicated in a “court case,” while a summary offense is adjudicated in a “summary case.”8 This distinction permeates the Rules of Criminal Procedure; Chapter 4 is devoted to “Procedures in Summary Cases,” while Chapter 5 governs “Pretrial Procedures in Court Cases.” Thus, in the present case, once the Commonwealth elected to charge Appellants with misdemeanor offenses, the Rules of Criminal Procedure determined the course by which Appellants would be prosecuted — as a “court case” under Chapter 5 of the Rules.
The role of a district justice in each type of case has also been carefully defined by statute and the Rules. Pursuant to Section 1515 of the Judicial Code, 42 *1171Pa.C.S. § 1515, a district justice serves as a committing magistrate in court cases and as trier of fact in summary cases.9 As a committing magistrate in a court ease, a district justice is charged with presiding over the preliminary hearing if not waived by the defendant. The purpose of a preliminary hearing is well-settled and stands in stark contrast to a summary trial, where the role of the district justice is to determine guilt or innocence:
The basic principles of law with respect to the purpose of a preliminary hearing are well established. The preliminary hearing is not a trial. The principal function of a preliminary hearing is to protect an individual’s right against an unlawful arrest and detention.... At this hearing the Commonwealth bears the burden of establishing at least a prima facie case that a crime has been committed and that the accused is probably the one who committed it.... It is not necessary for the Commonwealth to establish at this stage the accused’s guilt beyond a reasonable doubt.... In order to meet its burden at the preliminary hearing, the Commonwealth is required to present evidence with regard to each of the material elements of the charge and to establish sufficient probable cause to warrant the belief that the accused committed the offense.
Commonwealth v. McBride, 528 Pa. 153, 157-158, 595 A.2d 589, 591 (1991) (citations omitted). Further, pursuant to Rule 543 of the Rules of Criminal Procedure, “[i]f the Commonwealth establishes a prima facie case of the defendant’s guilt, the issuing authority shall hold the defendant for court. Otherwise, the defendant shall be discharged.” Pa. R.Crim. P. 543(A).
Thus, in view of the foregoing principles, we agree with the Commonwealth that the District Justice in this case had only two options at the close of the preliminary hearing: either hold Appellants for trial if the Commonwealth established a prima facie case or discharge Appellants if the Commonwealth failed to sustain its burden. The “third” option chosen by the District Justice, to usurp the Commonwealth’s prosecutorial discretion under the Act and sua sponte conduct a summary trial, simply has no foundation in the Judicial Code or the Rules of Criminal Procedure. The convictions rendered by the District Justice were a legal nullity.10
*1172In sum, we find no abuse of discretion by the trial court in issuing the writs of certiorari in this matter. The District Justice clearly overstepped his authority as a committing magistrate by usurping the Commonwealth’s prosecutorial discretion and sua sponte convicting Appellants of summary offenses. Accordingly, the order of the trial court is affirmed.
ORDER
AND NOW, this 14th day of March, 2005, the order of the Court of Common Pleas of Butler County in the above-captioned matter dated July 7, 2004, and entered July 9, 2004, is hereby AFFIRMED.