OPINION BY
Senior Judge McCLOSKEY.Marvin L. Price (Petitioner) petitions for review of a decision of the Pennsylvania Board of Probation and Parole (Board), which recommitted Petitioner to a state correctional institution to serve as a technical parole violator. We affirm.
Petitioner was originally sentenced in Allegheny County to an aggregate term of not less than five years to not more than ten years. (R. at 1). Petitioner’s minimum sentence date for these convictions was July 17, 2001, and his maximum sentence date is July 17, 2006. Id.
Petitioner was paroled on July 23, 2001, to the Renewal Community Corrections Center (the Renewal Center). (R. at 9-12). One of the conditions governing his parole required Petitioner to refrain from owning or possessing any firearms or weapons. Id.
On October 26, 2001, when Petitioner returned to the Renewal Center, a routine search was conducted by Renewal Center security monitor Lisa Tabb (Tabb) of a book bag believed by staff of the Renewal Center to belong to Petitioner. The book bag contained a pistol. Initially, Petitioner acknowledged ownership of the book bag, but then he denied ownership by stating that he grabbed the wrong bag at school.
On that same day, the Board issued a warrant to commit and detain, and Board agents arrested Petitioner for alleged violations of parole condition 5(b), relating to possession of a weapon, and parole condition 7, relating to unsuccessful completion of the Renewal Program. (R. at 13-15, 28).
As a result of the incident, the Pittsburgh police arrested Petitioner on November 9, 2001, and charged him with receiving stolen property,1 ownership of a gun by a former felon, and carrying a concealed weapon without a license. (R. at 18-20, 27). It appears that the charges were dismissed on October 3, 2003, due to the Commonwealth’s failure to subpoena witnesses in connection with the preliminary hearing. (R. at 15,17).
On or about January 21, 2004, a parole *175violation hearing was conducted.2 (R. at 37-70). By decision recorded on February 2, 2004, which was mailed on February 23, 2004, the Board recommitted Petitioner as a technical parole violator and sentenced him to serve twelve months backtime for violating parole condition 5(b). (R. at 72). In reaching this determination, the Board stated that it relied upon the testimony of security monitor Tabb and parole supervisor Roberta Troy. Id.
Petitioner filed a timely request for administrative relief. (R. at 75-76). By decision dated April 9, 2004, the Board denied Petitioner’s request for administrative relief, simply stating that “there was no reversible error during the revocation process.” (R. at 77).
On or about May 10, 2004, Petitioner filed a petition for review with this Court. On appeal,3 Petitioner argues that the Commonwealth failed to present substantial evidence to establish the parole violation by a preponderance of the evidence and that the Commonwealth violated Petitioner’s due process rights under the United States and Pennsylvania Constitutions by failing to preserve exculpatory evidence in the form of a video surveillance tape from the Renewal Center.
First, we will consider Petitioner’s argument that the Commonwealth failed to present substantial evidence to establish the parole violation by a preponderance of the evidence.
“Substantial evidence” is defined as “such relevant evidence as a reasonable mind might accept to support a conclusion of law.” Miller v. Pennsylvania Board of Probation and Parole, 105 Pa.Cmwlth. 24, 522 A.2d 720, 721 (1987). At a parole violation hearing, the Board is required to show by a preponderance of the evidence that the parolee violated the terms and conditions of his parole. Brown v. Pennsylvania Board of Probation and Parole, 806 A.2d 984 (Pa.Cmwlth.2002); and Hossback v. Pennsylvania Board of Probation and Parole, 80 Pa.Cmwlth. 344, 471 A.2d 186 (1984). A preponderance of the evidence is “such proof as leads the fact-finder ... to find that the existence of a contested fact is more probable than its nonexistence.” Sigafoos v. Pennsylvania Board of Probation and Parole, 94 Pa.Cmwlth. 454, 503 A.2d 1076, 1079 (1986). The Board may consider all the admissible evidence presented to it, but “its determination must rest on a foundation of substantial evidence.” Brown, 806 A.2d at 986. Moreover, it is the function of the Board, as the ultimate finder of fact, to evaluate witness credibility, resolve conflicts in the evidence and assign evidentia-ry weight, and these are not matters for a reviewing court. Sigafoos.
At the hearing, Tabb testified that on October 26, 2001, she was working at the Renewal Center as a security monitor when Petitioner returned to the facility. (R. at 43-44). As part of her job, she inspects each resident and his belongings when the resident enters the Renewal Center. (R. at 44). On that day, Petitioner entered the facility. When Tabb went to perform the inspection, there was a bag sitting on the counter. (R. at 45). Tabb testified that she checked the bag and found a weapon inside of it. She asked to whom the bag belonged, and Petitioner *176said that it was his. Tabb testified as follows:
I asked three times are you sure that this is your bag and he said yes that’s my bag and I asked again are you sure this bag is yours? And he stated yes that is my bag and then he said that’s not my bag, that’s not my gun in the bag.
Id. Tabb further explained that after the fourth time she asked him, he said “yeah, that’s my bag then he said wait a minute. That’s not my bag, that’s not my gun. I must have picked up the wrong bag.” (R. at 45^16). Tabb testified that she did not show Petitioner the contents of the bag. (R. at 46).4
Tabb acknowledged on cross-examination that she did not remove the bag from Petitioner’s person. (R. at 48). Rather, it was sitting unattended on a desk. Id. She could not identify Petitioner as carrying that particular bag on that day. (R. at 56). She described the bag as a “regular black backpack” without stickers or drawings on it. (R. at 49). There was no name on the bag either. (R. 49-50). She testified that the bag also contained a little phone book that had inside of it a name tag with Petitioner’s picture on it which was issued by the Renewal Center and usually used to identify who is sleeping in each bed. (R. at 52-53). She further testified that she spoke with the police regarding this matter, but she acknowledged that the police report states that Petitioner’s “name was not found inside the book bag.” (R. at 53). Regardless, she says that the book and name tag were inside the bag that was turned over to the police. (R. at 54). She testified that the bag also contained some papers and books, a pharmacy bottle, a parking permit and a receipt that all had the name “Marvin Brown” listed on them. (R. at 55-56).
On cross-examination, Tabb also testified that she was aware that Renewal Center made a surveillance tape, but she did not know where it was or whether it was destroyed. (R. at 54-55).
Parole supervisor Troy also testified. (R. at 58). She testified that on October 26, 2001, she was called to assist with the arrest of Petitioner. (R. at 59-60). She testified that during Petitioner’s transport to a state correctional facility, she told him not to worry if the gun task force comes and the prints are not on the gun. Id. He responded that his prints were on the gun because Tabb let him touch the gun when she took it out of the bag. Id. The conversation then ceased. Id. Troy testified that she was not sure whether any fingerprint testing was ever done. (R. at 62-65).
As to the surveillance tape, Troy testified on cross-examination that she knew that Renewal Center has surveillance tapes, but she did not ask to see the tape. (R. at 65). She thought that Agent Warner may have viewed the tape. Id. She did not know whether the tape had been destroyed. (R. at 66).
Petitioner’s counsel read into the record a portion of the transcript from Petitioner’s preliminary hearing where a police detective stated that “no fingerprints were lifted off the gun.” (R. at 67).
Petitioner did not testify or present any witnesses.
Based upon the above described evidence, we cannot say that the Board erred when it determined that Petitioner violated parole condition 5(b) by having in his pos*177session a gun. In his brief, Petitioner questions the credibility of Tabb and Troy in an attempt to establish that the Board lacked substantial evidence to support its determination.5 However, as noted above, the Board is the ultimate fact-finder and is charged with the responsibility of evaluating witness credibility, resolving conflicts in the evidence and assigning evidentiary weight.6 Sigafoos.
Next, we will address Petitioner’s argument that the Commonwealth violated Petitioner’s due process rights under the United States and Pennsylvania Constitutions by failing to preserve exculpatory evidence in the form of a video surveillance tape from the Renewal Center. Relying on the United States Supreme Court’s decision in Morrissey v. Brewer, 408 U.S. 471, 92 S.Ct. 2593, 33 L.Ed.2d 484 (1972), for the proposition that a parole offender must have the opportunity to present witnesses and documents into evidence, Petitioner makes the argument that he was entitled to present the surveillance tape as evidence and that the Board, due to its relationship with the Renewal Center, had a duty to preserve the tape. Instead, the tape was destroyed.
Petitioner’s argument must fail for a variety of reasons. First, Morrissey does not require the Board to preserve potentially exculpatory evidence in the case at hand as suggested by Petitioner.7 Second, Petitioner miseharacterizes the testimony presented in this matter. The testimony does not establish that the tape was viewed and destroyed. Rather, Troy testified that an agent may have viewed the tape. Tabb and Troy testified that they did not know whether the tape was destroyed. Third, there is nothing to suggest that Petitioner ever requested that he be granted access to the tape. Under these circumstances, there can be no violation of due process rights.
Accordingly, the order of the Board is hereby affirmed.
*178 ORDER
AND NOW, this 14th day of December, 2004, the order of the Pennsylvaniá Board of Probation and Parole, which recommitted Petitioner Marvin L. Price to a state correctional institution to serve as a technical parole violator, is hereby affirmed.
. The police criminal complaint reads: "[t]he actor intentionally received, retained or disposed of movable property, namely, A BOOK-BAG VALUED AT LESS THAN $50.00, belonging to MELVIN BROWN, with no intent to restore it to the owner, knowing that such property was stolen or believing that it had probably been stolen...' (R. at 18).
. Petitioner waived his right to a preliminary hearing in the parole violation matter. (R. at 23).
. Our scope of review of a Board's recommit-tal order is limited to determining whether necessaiy findings were supported by substantial evidence, whether an error of law was committed, or whether constitutional rights were violated. Jackson v. Board of Probation and Parole, 781 A.2d 239 (Pa.Cmwlth.2001).
. On cross-examination, Tabb testified that Petitioner had been at the Renewal Center long enough to know that when he returned to the facility, he and his bag would be searched. She had previously searched a bag belonging to Petitioner. (R.R. at 47-48).
.Petitioner contends that the testimony of Tabb was incredible because it does not make sense that Petitioner would have known that a gun was in the bag if Tabb did not show the contents of the bag to him. Also, Petitioner appears to argue that it does not make sense that he would try to bring a gun into the Renewal Center since he knew that his bag would be searched. Also, he points out the discrepancy between Tabb’s testimony regarding the phone book and the police report that states that nothing in the bag contained Petitioner’s name. He also takes the position that if his name tag was in the bag, someone could have taken it off his bed and put it there. Petitioner suggests that the evidence reveals that the bag belonged to Marvin Brown, not Petitioner. We note that there is no evidence of record whatsoever regarding Marvin Brown, or Melvin Brown, as identified in the police criminal complaint.
As to Troy, Petitioner questions her credibility by suggesting that if Petitioner had said to her that his fingerprints were on the gun, then Troy should have requested that Petitioner make a written statement to that affect and Troy should have told the police detective about the statement and testified at trial. We note that there is no evidence of record that she did not tell the detective about the statement.
. Additionally, we note that Petitioner did not provide any testimony or other evidence to show that he was never in possession of the bag and gun or to explain that his possession of the items was mistaken, although he appears to argue both in his brief. His argument is based entirely on supposition and not on evidence.
. In Morrissey, the United States Supreme Court held that minimal due process requirements for parole include a preliminary inquiry in the nature of a preliminary hearing to determine probable cause, to be conducted at or reasonably near the place of the alleged parole violation or arrest as promptly as convenient after arrest, and a revocation hearing with respect to which certain specified minimum due process requirements must be observed. Morrissey did not address any issues specifically relating to the preservation of potentially exculpatory evidence.