Worcester District Attorney Joseph Early Jr. said Monday that 27-year-old Vanessa Marcotte was reported missing after failing to return from a run between 1pm and 4pm in Princeton.
Her body was discovered at around 8.20pm Sunday by a state police K9 unit near Brooks Station Road, about a half-mile from her mother's home.
A source told Fox25 in Boston that investigators were examining the possibility that Marcotte was sexually assaulted and set on fire, with burns to her hands, head and feet.
Authorities would not specify how she died but say her death appears to be a homicide. An autopsy is scheduled.
'We have a horrible set of facts, horrible circumstance,' Early told reporters during a news conference.
He added that it was unclear whether Marcotte's killing was a random act of violence and urged local residents to remain vigilant and exercise caution.