Byrd fled the scene, leaving "the passenger trapped in the vehicle," Dudek said.
Butt was extricated and EMS personnel performed CPR on the way to University of Maryland Upper Chesapeake Medical Center in Bel Air, where she was pronounced dead at 10:28 p.m., according to State Police.
Troopers later found Byrd in the area. She tested negative for drug and alcohol impairment, Dudek said.
She initially told troopers she left the scene because she thought there was a warrant for her arrest; there was not, Dudek said.
Byrd was complaining of injuries from the crash and requested to be taken to Upper Chesapeake, Dudek said.
A visitation is scheduled for Butt from 1 to 4 p.m. Sunday at Kurtz Funeral Home, of Jarrettsville, according to her obituary posted online. A funeral is scheduled for noon Monday at the funeral home; burial will be in Highview Memorial Gardens in Fallston.