Karen Benjamin, 56, of Coram, was pronounced dead nearly a month after the crash in Mount Sinai.
Vehicular Crimes Unit detectives are continuing the investigation as the hunt for the driver continues.
Police believe Benjamin was jogging along Canal Road when she was struck around 11 a.m. She lives about two miles from the accident scene.
The impact was so violent that doctors say she nearly lost both of her legs.
"I just don't understand why someone would do this and not stop," daughter Lindsay Benjamin said. "Just stop."
Authorities in Suffolk County say they are looking for a light-colored 2000 to 2003 BMW sedan or station wagon.
Detectives are asking anyone with information to call Crime Stoppers at 1-800-220-TIPS. All calls will be kept confidential.
