The family of Bryan Christopher Kohberger, the suspect arrested in the brutal slayings of four University of Idaho students, have said they are cooperating with law enforcement to “promote his presumption of innocence rather than judge unknown facts and make erroneous assumptions”. Michael and Marianne Kohberger, and his sister, Amanda, spoke out on Sunday in their first public statement since the 28-year-old criminal psychology graduate was arrested early on Friday. They said they wanted to “let the legal process unfold and as a family we will love and support our son and brother”. The suspect’s family members also offered condolences for the families of the four students, saying: “First and foremost we care deeply for the four families who have lost their precious children. There are no words that can adequately express the sadness we feel, and we pray each day for them.” Kohberger has been charged with four counts of first-degree murder in the fatal stabbings of Madison Mogen, 21, Kaylee Goncalves, 21, Xana Kernodle, 20, and Ethan Chapin, 20. He was arrested at his parents’ home in Monroe county, Pennsylvania, 2,000 miles (3,219 km) from where the killings occurred in Moscow, Idaho, on 13 November. The suspect’s public defender, Jason LaBar, said in a statement that his client is “eager to be exonerated of these charges”. The attorney said Kohberger will not contest extradition to Idaho at a hearing on Tuesday. Kohberger’s arrest came after seven weeks of investigation during which the university town was gripped by anxiety and grief. The suspect lived on campus at nearby Washington State University, about a 15-minute drive from the slain students’ rental home. Moscow police chief James Fry on Saturday told Fox News that investigators were still “putting pieces together.” In the days after the killings, the suspect was teaching at his university, but later drove across country. “Sometime right before Christmas we were zeroing in on him being in or going to Pennsylvania,” a police source told CNN. LaBar told has said that Kohberger is “shocked a little bit” by his arrest.