With an uncanny knack for staying a step ahead of his own failings, court records show, Richard A. Brown either resorted to legal action or squirmed silently through loopholes in the regulations governing medical practice in Pennsylvania. He encountered little interference from the state, until he was arrested in December 2001 and pleaded no contest to a felony drug charge in 2003, resulting in five years' probation and suspension of his medical license. But he continued practicing medicine and illegally dispensing narcotics, prosecutors allege. Brown was able to get as far he did because Pennsylvania, according to some, is among the weakest states in disciplining wayward doctors.