When reviewing a prison disciplinary decision, this Court must decide only whether the determination was supported by substantial evidence (see CPLR 7803 [4]; Matter of Lahey v Kelly, 71 NY2d 135, 140 [1987]; Matter of Igartua v Selsky, 41 AD3d 717 [2007]; Matter of De La Cruz v Selsky, 36 AD3d 907 [2007]; Matter of Ramsey v Phillips, 11 AD3d 470 [2004]; Matter of Glover v Goord, 262 AD2d 483, 484 [1999]). Substantial evidence “means such relevant proof as a reasonable mind may accept as adequate to support a conclusion or ultimate fact” (300 Gramatan Ave. Assoc. v State Div. of Human Rights, 45 NY2d 176, 180 [1978]).
Here, a review of the record, including the misbehavior report, the “unusual incident” report, and the hearing testimony, reveals that there was substantial evidence to support the respondent’s determination that the petitioner violated prison rules. Credibility issues were resolved by the hearing officer, as the trier of fact, and we find no basis to disturb the determination (see Matter of Gilzene v McGinnis, 300 AD2d 658, 659 [2002]; Matter of Ramos v Goord, 286 AD2d 392 [2001]; Matter of Rivera v Selsky, 266 AD2d 295 [1999]).
There is no evidence in the record to support the petitioner’s contention that the hearing officer was biased (see Matter of Hughes v Suffolk County Dept. of Civ. Serv., 74 NY2d 833, 834 [1989]; Matter of Galdamez v Davis, 11 AD3d 535, 536 [2004]). Moreover, the hearing was timely concluded pursuant to valid extensions granted for the purpose of obtaining the testimony of witnesses requested by the petitioner (see Matter of Johnson v Goord, 297 AD2d 881, 882 [2002]; Matter of Mason v Goord, 271 AD2d 779, 780 [2000]; Matter of Stokes v Goord, 254 AD2d 558 [1998]).
*547The petitioner’s remaining contentions are not properly before us since they were not raised before the hearing officer. Rivera, J.P., Miller, Dillon and Belen, JJ., concur.