(NewsNation) — As the University of Idaho stabbing investigation enters its fourth week, some family members of the victims want more transparency from investigators. But experts say there are reasons why authorities may keep information close to the vest.

“I just feel like there’s been a couple individuals that were cleared very fast that maybe should not have been,” Kristi Goncalves, mother of victim Kaylee Goncalves, told NewsNation in an exclusive interview Sunday.

Kaylee Goncalves, 21, Madison Mogen, 21, Xana Kernodle, 20 and Ethan Chapin, 20, were stabbed to death in a rental home near the University of Idaho campus Nov. 13.

The family wants more clarity about how some individuals were cleared so quickly.

But it’s not uncommon for law enforcement to withhold information that could compromise the investigation, one expert told NewsNation.

“There’s a number of reasons for it: to avoid copycatting, to avoid bogus tips, bogus confessions — the whole back evidence can be used to basically calibrate the veracity of a confession,” said Michael Arntfield, a criminologist and co-director of the Murder Accountability Project, a nonprofit that focuses on unsolved murders.

In other words, authorities don’t want the public to have information that only the killer would know — for example, revealing which victim the attacker killed first, Arntfield said.

Additional information about cleared individuals could end up doing more harm than good and further overwhelm investigators who are already dealing with thousands of tips. On Saturday, the Moscow Police Department provided data showing the scale of the investigation:

• More than 2,645 emails have been received through the tip email address (tipline@ci.moscow.id.us)
• More than 2,770 calls have been made to the Tip Line at 208-883-7180
• More than 1,084 digital media submissions have been sent to the FBI link
• A total of 113 pieces of physical evidence have been collected
• There are approximately 4,000 crime scene photographs
• Multiple three-dimensional scans have been made of the residence

“Only vetted information that does not hinder the investigation will be released to the public,” Moscow Police said Saturday. “There is speculation, without factual backing, stoking community fears and spreading false information.”

Investigators also want to avoid incriminating innocent people, especially with the rise of amateur social media sleuths.

After giving a TV interview following the attacks, a nearby neighbor and third-year law student said he was harassed by people on the internet who decided his nervous smile was cause for suspicion.

“People online have been ruthless,” the man told NewsNation’s Ashleigh Banfield. The amateur investigators became so convinced that they began contacting the neighbor’s friends and family. He now carries a pistol for protection.

So far, around a half-dozen people linked to the case have been ruled out as suspects, police said. Those individuals include:

• The two surviving roommates who were sleeping on a separate floor at the time of the attack
• A male seen in a Grub Truck surveillance video
• The driver who took Kaylee Goncalves and Madison Mogen home Nov. 13
• The male Goncalves and Madison called numerous times during the early morning hours of Nov. 13
• Any individual at the residence when 911 was called

On Sunday, sources told NewsNation that Kaylee Goncalves’ injuries were “significantly more brutal” than her best friend Madison Mogen’s, who was sleeping in the same bed.

Investigators said they have looked into claims that Kaylee Goncalves had a stalker but have not verified or identified such an individual.

The Goncalves family told NewsNation they just want to understand the process better as the investigation approaches its fourth week. 

“We don’t want to make more victims out of innocent people,” Steve Goncalves said. 

Police can always re-evaluate a person they have “cleared.” In fact, publicly clearing someone could give the killer a false sense of security that leads to a mistake.