The bus driver with the Metropolitan Transportation Authority who was charged in connection with a crash that killed a 70-year-old woman on Tuesday in Brooklyn had been arrested three times over the last decade, a law enforcement official said.

The driver, Paul Roper, 48, appeared in court on Wednesday, charged with leaving the scene of an accident, a felony; failure to yield to a pedestrian, a misdemeanor; and failure to exercise due care, a traffic violation.

His earlier arrests, for drug possession and for assault in 2007, and for assault in 2012, are sealed and were described by a law enforcement official who spoke on the condition of anonymity because the cases were sealed. Other details of the arrests were not available, nor were their outcomes.

The transportation authority, where Mr. Roper has worked as a bus driver for 15 years, was notified about the arrests when they took place but had no basis to act against him, said Amanda Kwan, a spokeswoman for the agency.