Howard Safir, a New York City police commissioner during the Giuliani administration, backed his sport utility vehicle into a pregnant woman on the Upper East Side on Friday afternoon and then drove away, the police said.

The woman, Joanne M. Valarezo, 30, of the Bronx, was not knocked down and was not seriously injured in the accident, which occurred at 2:25 p.m. in front of 1418 Third Avenue, the authorities said. They said she was able to jot down the license plate of Mr. Safir’s black 2009 Cadillac Escalade.

Ms. Valarezo was taken by ambulance to New York-Presbyterian Hospital/Weill Cornell Medical Center, where she was treated for a bruised shoulder and then released, the police said. Ms. Valarezo’s unborn child, nearing its seventh month, was apparently not affected, she later said.

Detectives from the 19th Precinct tracked Mr. Safir down, questioned him and “determined there is no criminality,” said a law enforcement official. The detectives determined that Mr. Safir was unaware that he had struck the woman before driving away, another law enforcement official said.