Idaho Students' Killer Was 'Comfortable' Using Knife—Former FBI Profiler

The person who fatally stabbed four University of Idaho students in their beds is someone who felt "comfortable" using a knife, a former FBI profiler told Newsweek.

Kaylee Goncalves, Madison Mogen, Xana Kernodle and Kernodle's boyfriend, Ethan Chapin were found dead in an off-campus rental house in Moscow on November 13.

Two weeks later, police said that no suspect has been identified and that "only vetted information that does not hinder the investigation will be released to the public."

Mary Ellen O'Toole, who retired as an FBI profiler in 2009, said the perpetrator is someone who arrived at the house with the intent to kill.

"This is somebody that came to that house in the early morning hours, with the intent not to have a conversation or start a fight, but to kill those people," she told Newsweek.

"When you're going to somebody's house in the middle of the night, when you expect that they're going to be sleeping, and you're bringing a very powerful weapon with you, one that you're comfortable using—I don't think that's the first time he's used that weapon—then that suggests that there's no more talking, there's no need for conversations, I'm going to kill you," she said.

"The reason I say kill is because the police reported multiple stabbing injuries to each victim."

O'Toole said the killer may be someone with experience breaking into people's homes. "For an offender to go into someone's home where there are six adults in a residential neighborhood, where there are other people, other houses around with people inside of those houses, this tells me that this is somebody that has experience going into strangers' homes," she said.

She also said it was likely someone familiar with the layout of the house and confident they would be able to leave the crime scene without being caught.

"The offender had to have some degree of confidence that there were no other people in there with guns and other weapons, alarms, other things that could have compromised the offender," O'Toole said.

"That requires some kind of knowledge about the inside of that house and how it was set up. There's a comfort with being inside a stranger's home and then killing the people that live there...those are features that I think are very important."

O'Toole said there was also "no guarantee" that the killer won't commit another crime.

"This offender is dangerous and what I mean by that is, there's no guarantee and the police know this...you can't be sure that this person might not re-offend," she said.

Police have said they believe the killings were targeted, but have not specified what made them think this or which victim or victims may have been targeted.

A victim could be targeted well in advance of an attack or just minutes before, according to O'Toole.

"But in this case, I think whoever the victim was that was targeted or the victims were who were targeted, there was some time between them being targeted and the offender getting into the house based on the offender's comfort level of being inside that home," she said.

Police may have determined who the target was by analyzing if any of the victims were treated differently, she added.

"Was there one victim or two, that had excessive stabbing injuries? Was there one victim or two victims whose bodies were posed?" she said. "Was there treatment of a victim in that household that differed from the other three or the other two? That would tell me that was the targeted victim...that maybe enabled the police to surmise there's one person in particular that the offender was after."

As the investigation continues, police on Tuesday took away five vehicles that had been parked outside the house since the night of the killings.

On Wednesday, mourners will gather for candlelight vigils at the University of Idaho's Moscow campus and other locations across the state to honor the slain students.