The state of Pennsylvania is quite lenient against first time offenders, excluding sex crimes adults (or children) and any crimes involved with the corruption of a minor. You are required to complete the ARD (Accelerative Rehabilitative Disposition) program in order to be considered for expungement, per 234 Pa. Code Rule 320; 18 Pa. C.S.A. § 9122. For those that were 21 or older at the time of their conviction for possession, consumption or purchase-related offenses are eligible for having their records and arrest record expunged via 18 Pa. C.S.A. § 9122.