A linked person for the murders of four University of Idaho students has been arrested in Pennsylvania, police sources said Friday.

Police in Moscow, Idaho, have scheduled a news conference for 1 pm PT, where they are expected to reveal more details about the November murders that shocked the small college town.

The arrest was made in Monroe County in northeastern Pennsylvanialaw enforcement sources told NBC News.

Ethan Chapin, 20, of Conway, Wash.; Madison Mogen, 21, of Coeur d’Alene, Idaho; Xana Kernodle, 20, of Avondale, Ariz.; and Kaylee Goncalves, 21, of Rathdrum, Idaho, were killed on November 13.

From top left, Kaylee Goncalves, Madison Mogen, Ethan Chapin, and Xana Kernodle.

Three of the victims shared the house, Goncalves, Mogen and Kernodle, while Kernodle’s boyfriend, Chapin, was staying overnight, according to investigators.

Authorities believe they were killed inside the apartment building in their sleep, though some had defensive wounds.

Police were also searching for the weapon, believed to be a large knife.

Two other roommates were home at the time of the killings in the early hours of November 13, but police said they are not believed to have been involved in the crime.

Two were asleep during the stabbings, and one of their cell phones was used to call 911 when they woke up later that morning, detectives said.

The investigation was led by Moscow police, with dozens of state and federal agents providing forensic analysis of a scene experts say was complicated by the nature of the crime, a quadruple homicide, and the fact that the co-workers fourth year they would organize parties.

As weeks passed without an arrest or person of interest being named, the case caught the attention of internet detectives, prompting police to dispel unsubstantiated claims on social media.

Moscow Police Chief James Fry insisted the case was not cold.

He also declined to speak in detail about the case or investigators’ best leads, telling NBC News last week that police must protect the integrity of the investigation and also don’t want to contaminate a potential jury pool if there is a trial. .

«I know that’s very frustrating,» Fry said. “It is frustrating for family members and [the] community, but our ultimate goal is to bring someone to justice for those families and those victims.”

Initially, the case was dogged by mixed messages from authorities, who first told the public that the «targeted attack» did not pose a persistent threat to the community. But Fry, days later, said that he couldn’t say where the killer or killers might be.

An arrest comes as a «celebration of life» was planned later Friday for two of the roommates, Goncalves and Mogen.

This is a developing story. Please check for updates.

david k li Y erik ortiz contributed.