A Cambridge man charged with motor vehicle homicide was released on personal recognizance by a Newton District Court judge yesterday following his arraignment, the Middlesex District Attorney's office said today.

Detlev Vagts, 81, a retired Harvard professor, is charged with motor vehicle homicide in connection with a fatal accident that resulted in the death of Marcia Kearney, 54, of Northampton.

Vagts was released by Judge Dyanne Klein on the condition that he does not drive, the DA's office said.

The defendant is scheduled to be back in court on March 2.

According to the DA's office, on July 8, Vagts, who was driving a Subaru Legacy sedan, allegedly struck Kearney from behind as she was making a left-hand turn from Ward Street on to Grant Avenue. Kearney, who was riding a Vespa, flew 82 feet from the site of the crash.

Kearney was transported to Beth-Israel Deaconess Medical Center where she was pronounced dead.

Investigators allege that Vagts did not keep right and was partially traveling in the opposite lane on Ward Street. The DA's office says Vagts drove nearly 450 feet before traveling back to the accident scene.