Idaho police have distanced themselves from claims that the unsolved murder of four students poses no danger to the public, saying: "There is a threat out there still."
Officials in the small college town of Moscow had insisted that there was "no imminent threat to the community at large", despite identifying no suspects.
Investigators do not yet know who killed Ethan Chapin, Madison Mogen, Xana Kernodle, and Kaylee Goncalves with an "edged weapon" in the small hours of Sunday morning.
On Tuesday, Moscow police chief James Fry admitted that the killer could still be at large, partially walking back the department's previous statements.
Asked at a press conference how he could be sure there was no danger, Mr Fry said: "That's kind of unknown... we still believe it's a targeted attack, but the reality is, there's still a person out there who committed horrible, horrible crimes.
"So there is a threat out there still, possibly. We don't know it's going to be to anybody else. But we all have to be aware of our surroundings and make sure that we're watching out for each other."
He expressed regret over the limited information given by police over the preceding two days.
"We had a lot of information coming in, and we have tried to push out some information through press releases.
"The reality is, I probably should have been up here a day or so ago. But I'm here now. We're going to continue to be here. We're going to continue to give you the information we can.
"I care about this community. I've worked here for 27 years. I want this community to be the safest community around.... we're looking at every aspect of this."
The four murders have rocked Moscow's student community, prompting a lockdown on campus and outpourings of support.
But some residents and relatives of the victims had expressed doubts about the police claims, questioning how there could be no threat to the public when the killer was still at large.
"I’m not sure if people who aren’t directly tied to the University of Idaho in some way understand how little information students, parents and community members have gotten about the murder of four students in an off-campus apartment two days ago," said Annie Reneau, who said she was the mother of a University of Idaho senior.
