In November, four University of Idaho students were killed in their off-campus home, prompting investigations by the FBI, state police and Moscow city police.
Now federal law enforcement officials tell CNN that a suspect has been taken into custody.
Here is a timeline of some key events in the case:
November 12: Kaylee Goncalves, Madison Mogen, Ethan Chapin and Xana Kernodle are University of Idaho students who live in off-campus housing near Moscow, a university town of about 25,000 people. They share two other flatmates in the three-storey, six-bedroom apartment.
That night, Chapin and Knodel went to a party on campus, and Morgan and Gonsalves went to a downtown bar, police said.
November 13: Mogen and Goncalves ordered from a late-night food truck around 1:41 a.m., the food truck’s live Twitch stream showed. If they’re waiting for food, they can be seen chatting to each other and to other people standing by the truck.
Joseph Woodall, 26, who managed the truck, said the two students did not appear to be in any difficulty or danger.
Chapin and Kernodle are believed to have returned home around 1:45 a.m., while Goncalves and Mogen were driven home from a private party at about 1:56 a.m., according to police.
Two other roommates in the home who were not injured woke up later in the morning and called friends home because they believed one of the victims was passed out and hadn’t woken up. Just before noon, 911 was called with reports of an unconscious person at the residence, police said.
Arriving police found the door of the residence open and the bodies of the four stabbed students.
Police said there were no signs of forced entry or damage.
November 15: Moscow police said in a statement that “sharp weapons such as knives” were used in the killing. Police said no suspects were in custody and no murder weapon was found.
November 16: Police Chief James Fry called a news conference — the department’s first on the case — and reiterated that there were no suspects. He also noted that two other roommates who were home at the time of the attack were not injured. The official said authorities were not focusing on them.
“We are looking at everyone who may have entered or exited the residence,” he told reporters.
November 18: Investigators said they had determined the victim was “probably asleep” before the attack.
By then, detectives had conducted 38 interviews with people who “could have knowledge” of the killings and had taken the contents of three dumpsters near the house for later use, they said. Investigators also asked local businesses if they had recently purchased “straight-edged knives,” according to the police update.
To get a tip from the community, investigators released a map and timeline of the victims’ movements over the weekend. The map shows that the four students spent most of their time in pairs and separately.
November 20: Police have received 646 tips and conducted more than 90 interviews, Commissioner Frye said at a news conference. He declined to say who called 911 from the home where the student was killed, saying only that the call was from a surviving roommate. He would not confirm who made the call, but said the caller was not a suspect.
November 30: Moscow police released a list of people they don’t think were involved in the crime, including two surviving roommates, a man in Grub Truck surveillance video, and the private party driver who brought home Goncalves and Mogen, who were on multiple occasions Call the man the night they were killed, and anyone who was home when 911 was called. Police believe the attack was indeed “targeted,” but investigators have yet to determine whether the residence or residents were targeted.
December 5: Regarding Goncalves’ possible stalker, police said investigators uncovered an incident in October when two men were seen at a business, one of whom appeared to follow Goncalves into the house. And followed her when she got out of the car. The man did not contact her.
Investigators contacted the two men and learned they were trying to meet women at the company. Detectives said they believed it was an isolated incident, not stalking, and said there was no evidence the men were involved in the killing.
December 7: Investigators said they were interested in speaking with the occupants of a white 2011-2013 Hyundai Elantra found near the crime scene around the time of the homicide.
CNN’s Veronica Miracle, Jason Kravarik, Ray Sanchez, Andi Babineau, Caroll Alvarado and Sharif Paget contributed to this report.