The driver behind the Cambridge hit-and-run that injured a 77-year-old woman in a wheelchair has been identified, authorities announced Thursday.

A Somerville resident was the driver of the vehicle who caused the crash around 4:40 a.m. Sunday, and the vehicle has also been located, Middlesex County DA Marian Ryan and Cambridge Police said.

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"This remains an open and active investigation and no charges have yet been filed," Ryan's office said in a statement.

The victim, identified as 77-year-old Dorothy Steele by ABC, remains in critical condition days after the crash.