By Brendan O'Brien

(Reuters) -A judge on Monday entered a not guilty plea on behalf of the graduate student charged with murder in the fatal stabbing of four University of Idaho college students, local media reported.

Bryan Kohberger, 28, remained silent and opted not to enter a plea during an arraignment hearing in Latah County, CBS2 News in Boise reported, prompting District Judge John Judge to enter the plea for him.

Last week, a grand jury indicted Kohberger on four counts of murder and one count of burglary.

Kohberger is accused of stabbing three women and one man in the early morning of Nov. 13 in the home of one of the women. The crime stunned the small college town of Moscow, Idaho, home to the University of Idaho, and drew national attention, with six weeks elapsing before a suspect was caught.

Kohberger eventually was arrested in Pennsylvania, where he was visiting his family, and flown to Idaho to face charges.

Two other female roommates in the house at the time of the killings were unharmed. One of the women told investigators that at 4 a.m. she heard someone crying in one of the victim's bedrooms. She then watched as a masked man, clad in black, walked past her and out of the house, according to a court document.

The victims - Ethan Chapin, 20, of Conway, Washington; Xana Kernodle, 20, of Avondale, Arizona; Madison Mogen, 21, of Coeur d'Alene, Idaho; and Kaylee Goncalves, 21, of Rathdrum, Idaho - all suffered multiple stab wounds. Chapin was Kernodle's boyfriend.

Kohberger at the time was working on a doctorate degree in criminal justice at Washington State University, about 10 miles (16 kilometers) from the University of Idaho campus.

Authorities have not publicly disclosed a motive but have said they are confident Kohberger was responsible for the killings.

(Reporting by Brendan O'Brien in Chicago, Editing by Rosalba O'Brien)