The investigation into the murders of four University of Idaho students enters a critical phase in its third week as police begin to receive forensic test results from the crime scene, law enforcement officials tell CNN.
Dozens of local, state and federal detectives have yet to identify a suspect or locate the murder weapon used in last month’s attack in Moscow.
The public, as well as the victims’ relatives, have criticized the police for releasing little information, in what has at times been a confusing narrative.
But the complex nature of a high-level murder investigation requires the utmost discretion on the part of police, experts say, because any premature hint to the public about a suspect or the various leads the police follow could cause it to fall apart.
“What the police don’t like to do in this case is say they have a suspect, even though they’ve had suspects that have risen and fallen on different levels of importance, because that’s the nature of the beast,” said John Miller, CNN Chief Law Enforcement Analyst and former New York Police Department Deputy Intelligence and Counterterrorism Commissioner.
“Police who have no suspects are factually incorrect,” Miller said. “The police have investigated a number of suspects, but they have no suspect to name. You don’t name them unless you have a purpose for doing so. That is not unusual.”
The Victims – Ethan Chapin, 20; Kaylee Goncalves, 21; Xana Kernodle, 20; and Madison Mogen, 21 — were stabbed on Nov. 13 on the second and third floors of their shared off-campus home, according to authorities.
The quadruple homicide has rocked the city of 26,000, which has not recorded a single homicide since 2015, and challenged a police department that has not benefited from the experience of investigating many murders, let alone the pressure of a national audience, says Miller. .
Moscow police are leading the investigation with help from the Idaho State Police, the Latah County Sheriff’s Office and the FBI, which has assigned more than 40 officers across the United States to the case.
“They really coordinated this into over 100 people operating as one team,” Miller said of the murder investigation.
According to Miller, the FBI plays three major roles in the Idaho investigation.
The first concerns the behavioral science unit, which is very valuable for cases with an unknown perpetrator because it narrows the scope of perpetrator characteristics.
The second is advanced technology, such as the Combined DNA Indexing System, which allows law enforcement and crime labs to share and search thousands of DNA profiles.
Finally, the FBI maintains 56 field offices in major cities across the country, which can increase the reach and capacity of the investigation.
“The FBI brings a lot to this, as well as experience in a range of cases beyond what a small town would typically have,” Miller said.
Every murder investigation begins with the scene of the crime, giving investigators only one chance to capture and collect forensic evidence for processing, including toxicology reports on the victims, hair, fibers, blood and DNA, law enforcement experts say.
“That one shot at the crime scene is where many chances can be made or lost,” Miller said.
Extensive evidence was gathered in the course of the investigation, including 113 pieces of physical evidence, about 4,000 crime scene photos and several 3D scans of the house, Moscow police said Thursday.
“To protect the integrity of the investigation, specific results will not be released,” police said.
Latah County Coroner Cathy Mabbutt told CNN she saw “a lot of blood on the wall” when she arrived at the scene and police said “some” of the victims had defensive wounds.
The chances are “quite good” that a suspect cut himself during the attack, so police look carefully at blood evidence, says Joe Giacalone, an adjunct professor at the John Jay College of Criminal Justice and a retired NYPD sergeant who led the Homicide School and Cold from the Bureau Case Squad.
Lab results from the crime scene can be returned to investigators fairly quickly, but in this case investigators are dealing with mixtures of DNA, which can take longer, he says.
“If you have multiple donors with the DNA, separating those two, three or four becomes a problem. That could be part of the problem…toxicology reports can sometimes take a few weeks to come back,” Giacalone added.
The next stage in a murder investigation is looking at the behavioral aspects of the crime. Two agents from the FBI’s Behavioral Analysis Unit were assigned to the case to review the crime scene and review evidence to learn more about the behavior of the suspect or suspects, based on how they committed the crime says Miller.
“Understanding the victim role in a mystery can be very important because it can lead you to motivation, it can lead you to enemies and it can lead you to friends,” he said.
Investigators will learn every detail about the four victims, their relationships with each other and the different people in their lives, Miller says. This includes cell phone and internet data, he says, as well as video surveillance from every camera around the crime scene.
“If you do an extensive video search, you might get a picture of a person, a shadowy figure, and if you have a sense of direction, you can work your way past all the other cameras in that direction to see if that image shows up again,” Miller said.
At this stage, investigators rely on the FBI’s Violent Criminal Apprehension Program, which collects and analyzes information about violent crimes in the United States.
The program can match a suspect’s DNA found at the scene with that of a person already in the system. It also scans all crimes across the country to determine if the way the attack was carried out mirrors a previous attack, pointing to the same perpetrator, Miller says.
“You always start with people who are close to the victims, whether it’s love, money or drugs,” Giacalone told CNN. “That’s generally the first step you take because most of us fall victim to someone we know. We need to ask things like: who would benefit from this person, or in this case a group, being killed?”
In an attempt to locate the weapon — believed to be a fixed-blade knife — detectives contacted local businesses to see if a similar knife had recently been purchased.
“It is highly unlikely, although not impossible, that a first-time offender will be prepared with a tactical knife and kill multiple people, even in the face of resistance, and that this will be their first encounter with violent crime or the use of a knife,” Miller said.
One aspect of a murder investigation is to “keep the media happy,” according to Giacalone.
“Today the demand for information in the social media, true crime, community driven world in these cases is so great that police departments sometimes fill in that blank and say something just to say something, and then realize it either isn’t 100% either true or misleading,” he said.
It is critical for the police to protect their information at all costs and they always know more than what they release to the public. Otherwise, the suspect could flee, he says.
Miller said it’s “not fair” to investigators for the public or media to criticize them for not releasing enough information about the case.
But ultimately, the department has a moral obligation to share some information with families living in uncertainty, Miller says, but they need to be thoughtful about what they share.
“If you tell them we have a suspect and we’re close to an arrest but that doesn’t come together, everyone is disappointed or thinks you messed up or worse, go out and find out who the suspect is and try take action yourself,” he said.
Investigators rely on the wealth of physical and scientific evidence, information from the public and national data on violent crimes to find potential leads, Miller says.
Public tips, photos and videos from the night the students died, including more than 260 digital media submissions people submitted through an FBI form, are being analyzed, police say. Authorities have processed more than 1,000 tips and conducted at least 150 interviews to move the case forward.
“Any one of those tips could be the missing link,” Miller said. “It could be the connective tissue of a clue you already had but missed a piece, or it could become the brand new clue that solves the case.”
Every tip should be recorded in a searchable database so investigators can refer back to it if they uncover new details as the investigation progresses, Miller says. While 95% to 99% of public tips may be worthless, one or more tips can solve the whole thing, he adds.
“The police on this case can’t be anywhere tonight after they flush out another suspect, and they could make an arrest tomorrow morning,” Miller said of the Idaho investigation. “Or, for the suspect they’re working on today, it could be another month from now until they gather enough evidence to have a probable cause. That’s something they can’t reveal until it happens.”