Mystery surrounds the death of New Jersey college student who went missing just before Thanksgiving and was found dead at a state forest reserve — the victim of a homicide, cops said Friday.

Search crews stumbled upon the body of 20-year-old Sarah Butler at around 11:30 a.m. Thursday while trekking through the Eagle Rock Reservation in West Orange, according to NJ.com.

The Essex County Prosecutor’s Office ruled her death a homicide on Friday afternoon and told the outlet that it appeared her remains had been placed there by someone.

“We are trying to piece the timeline together,” explained Chief Assistant Prosecutor Thomas Fennelly. “It is an extremely active investigation.”

Authorities have not revealed where they found Bryant’s body in the 400-acre park and have yet to give her exact cause of death.

“The mystery behind her disappearance and ultimate loss of life is unsettling,” said Jo Ann Short, president and CEO of the Montclair YMCA, where Butler worked as a lifeguard.

“As a 20-year-old college student, she had a bright and promising future ahead of her,” Short added. “Her family is grieving and we pray for answers so their healing can begin.”

Butler — a freshman at New Jersey City University in Jersey City who loved to dance and performed at the Apollo Theater on numerous occasions — was first reported missing on Nov. 23 after she failed to meet up with her family for a scheduled trip to Jamaica.

The Montclair native’s father, Victor Butler, has been out searching for his daughter ever since and was devastated to learn the news about her death.

“I couldn’t help her,” he told CBS. “That is the most hardest part…The family’s having a hard time. We all are…It was senseless.”

A makeshift memorial was placed outside Butler’s home on Friday just hours after cops revealed that she had been killed.

“Not my Sarah, not my Sarah,” cried her mom, LaVern Butler, who was one of several at the scene.

“Whoever did this is a dog,” she said, according to ABC.

Butler — who lived on NJCU’s campus and was studying media arts — was last seen on Nov. 22 driving her mother’s 2007 Dodge Caravan, which was later found abandoned in Orange. What she was doing at the time is still unclear.

“She had so much more to give, and now we can only hope that her killers are caught,” said Pluchet Alexander, a family friend. “This is a family’s worst nightmare. She never did anything to hurt anyone and was loved by all.”

The Essex County Crime Stoppers Program has announced a reward of up to $10,000 for any information leading to an arrest.

“She was the sweetest thing I ever had, and she’s gone now,” Butler’s aunt, Phyllis Carpenter, told CBS. “Somebody took her away.”