The death of a 20-year-old Montclair woman who went missing and was later found dead in West Orange has been ruled a homicide.

Investigators have determined that Sarah Butler's body was placed in an area of Eagle Rock Reservation in West Orange.

The Essex County Prosecutor's Office has not said how Butler died, but an autopsy is underway. The Essex County Homicide Task Force is investigating.

Butler was last seen Nov. 22 around 8 p.m. Her friends and family had been searching for her ever since. They placed missing person fliers all around Montclair, as well as around the campus of New Jersey City University, where Butler was a student.

Friends tell News 12 New Jersey that Butler was last seen driving her mother's Dodge Caravan, which was found before he body was discovered.

Anyone who may have any information on Butler's disappearance and death is asked to call the prosecutor's tip line at 877-847-7432.

Crime stoppers is offering a reward of up to $10,000 for information leading to an arrest and conviction in this case.