The deaths of four University of Idaho students found stabbed over the weekend were officially ruled homicides, authorities said.
Latah County Coroner Cathy Mabbutt said the manner of death was a stabbing for all four individuals. The cause of death was murder, according to Mabbutt.
The victims are Ethan Chapin, 20; Madison Mogen, 21; Xana Kernodle, 20; and Kaylee Goncalves, 21, who police say were attacked with an "edged weapon," likely a knife.
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Mabbutt, who wrapped up the autopsies Wednesday, previously said the killings were not a murder-suicide. The toxicology reports are still outstanding. She said the same knife was likely used to kill all four victims.
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Police have not recovered a weapon or publicly identified a suspect in the quadruple homicide, which has shaken the small town of 25,000 people.
Scott Jutte, a manager at Moscow Building Supply, told the Idaho Statesman that police had come by more than once asking if the store had sold any Ka-Bar brand knives, which they do not carry. The combat knife looks like the one used by Rambo, Jutte added.
Latah County Prosecutor Bill Thompson told NBC News that it's possible there's more than one suspect.
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"It certainly is possible. That's the purpose of the investigation, that's why we're really hoping for any information from the public that can help the investigators recreate everyone's activities from Saturday night into early Sunday morning and hopefully give them the leads, the information, to identify who did this," Thompson said.
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In a press conference Wednesday, Moscow Police Chief James Fry urged locals to "stay vigilant" as the "individual is still out there."
Police came upon a gruesome scene at noon Sunday after responding to a 911 call of an "unconscious individual" at the King Road home, where the victims and two female roommates lived.
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The roommates were home when the students were killed between 3 a.m. and 4 a.m., Fry said.
The FBI and the Idaho State Police are assisting in the investigation.