(NewsNation) — The suspect, or suspects, who allegedly stabbed four University of Idaho students to death on Sunday remains at large and unidentified as of Tuesday.

Authorities initially said they believe the killings were a targeted, isolated attack, and have assured the public that there was no imminent risk to the community.

During a news conference Wednesday, Police Chief James Fry said he couldn’t guarantee there is no wider threat to the community. “We don’t believe it’s going to be to anybody else, but we all have to be aware of our surroundings and make sure we’re watching out for each other.”

New video has surfaced showing two of the victims at a food truck the night of the killing. Police said the video has helped with the case, but investigators are still working to identifying one of the individuals seen in the clip.

The students, all close friends, were found dead in an off-campus rental home around noon on Sunday, and officials said they likely were killed several hours earlier.

There have been reports from neighbors saying they heard a party happening at the home, but nothing out of the ordinary.

Latah County Coroner Cathy Mabbutt told the Spokane, Washington-based television station KXLY that her preliminary investigation showed the students were stabbed to death. There is no indication that substance use was involved in the deaths, Mabbutt said.

A cause of death has not been officially revealed and autopsies scheduled for Wednesday could provide more information about the slayings.

“Crime knows no boundaries, and these murders have shaken us to our very core,” Idaho State Police Colonel Kedrick Wills said during the news conference. “Our hearts break for the families. The loss of their loved ones, the University of Idaho, the Moscow community, and our entire state.”

Wills assured that the Moscow Police Department and Idaho State Police are working closely together to make sure that whoever is responsible is brought to justice.

The victims have been identified as 20-year-old Ethan Chapin, 21-year-old Madison Mogen, 20-year-old Xana Kernodle and 21-year-old Kaylee Goncalves, according to a Facebook post by the university president, Scott Green.

According to the president’s post, Chapin was a freshman from Washington, a member of Sigma Chi fraternity and majoring in recreation, sport and tourism management. Mogen was a senior from Idaho, a marketing major and a member of Pi Beta Phi Sorority. Kernodle was a junior from Arizona, a marketing major and a member of Pi Beta Phi Sorority. Goncalves was a senior from Idaho, a general studies major and a member of Alphi Phi.

“Words cannot adequately describe the light these students brought to this world or ease the depth of suffering we feel at their passing under these tragic circumstances,” Green said on Facebook.

Counselors and security are being provided around campus by the University of Idaho, and classes were canceled Monday.

University officials announced that the vigil for the victims has been delayed as the incident has prompted many students to leave campus early for Thanksgiving break.

An investigation into this incident is ongoing.

The Associated Press contributed to this report.