(NewsNation) — Families are still looking for answers after four students at the University of Idaho were found stabbed to death inside their home.

Police spoke to the media for the first time three days after the bodies were found and backtracked on previous information that there was no threat to the public. No suspect has been named by police.

Alivea Goncalves, sister of victim Kaylee Goncalves, said she doesn’t blame the police for being overwhelmed, but noted, “We’re losing critical time” in the investigation.

From what Alivea understood about her sister’s life, there have never been any threats. She said there’s no high-risk lifestyle that could explain this, and it has taken her by shock.

“I don’t want to impede on anything. But I want more people speaking out. And if that takes the police to push that agenda, that’s fine. But unfortunately, I feel like it’s been me and the families pushing that agenda. And that’s been really difficult,” Alivea added.

Alivea said her sister was a “go-getter” and “an absolute fighter,” and they have no idea why she was the target of such a brutal slaying.

Alivea says she provided police with a video of her sister at a food truck hours before she died, and identified one of the men in the background who she says is cooperating with police.

Police say Kaylee and her roommate Madison Mogen were at a party on campus while Xana Kernodle and freshman Ethan Chapin were at downtown bar before they all arrived home early Sunday morning and were attacked sometime around 3 a.m.

A 911 call for an unconscious person came in at noon. Police say two other people were inside the apartment home at the time.

“I know who they were – I’ve not spoken to them. They were my sister’s roommates. Obviously, I know who she lived with. I’m thankful we didn’t lose more lives here,” Alivea said.

Officers have not identified a suspect or found a blade that was used to stab the students, Moscow Police Chief James Fry said Wednesday. But the Idaho Statesman reported this week that police are searching for a military-style knife in connection with the killings.

Scott Jutte, general manager of Moscow Building Supply, told the newspaper that officers have visited the store more than once to ask whether it sold anyone Ka-Bar-brand knives. Ka-Bar, of Olean, New York, manufactures military-grade blades that were originally designed for use by American troops in World War II, the Statesman said.

It’s these sorts of details Alivea hopes will encourage someone to come forward so she can get her sister and her friends justice.

“We’re losing critical time. I want more coverage, I want more done,” she said.

Grace Anderson, a high school friend of Kaylee Goncalves and Xana Kernodle, said she’s saddened to speak on behalf of her friends but hopes to share some positive things about them.

“I was lucky enough to have known these two beautiful girls, despite the fact that they were so much more than what my words can describe of them,” she said.

It’s unclear if the victims knew the suspect. Police have said evidence found at the scene leads them to believe that the students were targeted, though they haven’t given details.

Xana was bubbly and humorous, Anderson said.

“Xana was just such a light, and she was lively, tender-hearted,” she said.

Anderson said she didn’t know Kaylee as well as Xana, but she always checked in on her and made sure she felt “welcomed and seen” when she went to the university.

While a targeted attack is often an indication that the killer and victim knew each other on some level, police have also said they have no idea who committed these crimes, so it could have been a stranger. Investigators do say nothing appears to have been stolen from the victims or the home.

University of Idaho President Scott Green said the school will remain open the rest of the week because some students have found comfort there among faculty and classmates. But the school is also giving excused absences to anyone who feels more comfortable leaving early ahead of next week’s Thanksgiving holiday.

The Associated Press contributed to this report.