MOSCOW, Idaho -- A 28-year-old graduate student arrested in Pennsylvania in connection with the murders of four University of Idaho students is believed to be the only suspect in the high-profile case, authorities said.
"We believe we have our guy, the one that committed these murders," Moscow Police Chief James Fry told ABC News Saturday.
Fry said he does not anticipate additional arrests in connection with the murders of roommates Kaylee Goncalves, Madison Mogen and Xana Kernodle, and Kernodle's boyfriend, Ethan Chapin, who were all stabbed to death in the girls' off-campus house on Nov. 13.
'He was home for the holidays'
The suspect, Bryan Kohberger, was arrested early Friday at his parents' house in Pennsylvania's Pocono Mountains, where Kohberger went several days before Christmas, Monroe County Chief Public Defender Jason LaBar told CNN.
A white Elantra authorities had been looking for in connection with the killings was also at the parents' house, the attorney added.
"He was home for the holidays," LaBar said.
He is a graduate student at Washington State University, located less than 10 miles away from the University of Idaho, police said.
Washington State University identifies Kohberger as a Ph.D. student in its department of criminal justice and criminology. He completed his first semester in its criminal justice program earlier this month, the university said.
Kohberger's father traveled with him from Washington state to Pennsylvania, according to the public defender and a person who claims to have interacted with the father and son earlier in December.
That person, who asked not to be identified, said they did not know the father and son but engaged in friendly conversation with them at an auto maintenance shop on December 16 in Pennsylvania, while the two were getting their Elantra serviced. (A separate person also confirmed to CNN the father and son did business at the location on December 16.)
The father told the individual he flew to Washington state and made the cross-country trip with Kohberger, adding his son would be traveling to the west coast alone after the holidays. Police have not indicated the suspect's father is in any way implicated in the killings. CNN has attempted to contact the father for comment.
The person described the younger Kohberger as "a little awkward," but not suspiciously so. The suspect reportedly told the person he wanted to go into the field of behavioral criminal justice and become a professor.
Kohberger expected to waive extradition
Kohberger was arrested on four counts of first-degree murder and burglary and is being held without bond, Latah County Prosecutor Bill Thompson said. Kohberger is scheduled to appear in a Pennsylvania court on Tuesday to begin the extradition process, Thompson said.
Kohberger intends to waive his extradition hearing to "expedite his transport to Idaho" and is "eager to be exonerated of these charges," Jason Allen LaBar, a public defender representing the suspect for the hearing, said Saturday.
"Mr. Kohberger has been accused of very serious crimes, but the American justice system cloaks him in a veil of innocence. He should be presumed innocent until proven otherwise -- not tried in the court of public opinion," LaBar said in a statement. "One should not pass judgment about the facts of the case unless and until a fair trial in court at which time all sides may be heard and inferences challenged."
Police are still seeking the murder weapon -- believed to be a fixed-blade knife -- and do not have a motive, Fry said. The chief said police have evidence this was a targeted attack but cannot share more details at this time.
Within an hour of Kohberger being identified as the suspect, more than 400 calls came in to the Moscow Police Department's tip line, Fry said.
White Hyundai Elantra found
A white Hyundai Elantra spotted near the victims' house around the time of the crime is believed to be Kohberger's, Fry said.
Police had previously said they believe the occupant had "critical" information in the case. Police do not believe anyone else was in the car at the time, Fry said.
Law enforcement personnel seized the car from Kohberger's parents' Pennsylvania home and it is being processed, according to Fry.
On lack of transparency
The probable cause affidavit, which details the reasons for Kohberger's arrest, is sealed and cannot be released until he returns to Idaho, Thompson said.
Once it is unsealed, more information, such as Kohberger's whereabouts over the past several weeks and what led police to the Hyundai Elantra, will be made public, Fry said.
Frustrations had been mounting among some of the victims' family members in the wake of the murders and what was criticized as a lack of transparency from police.
Fry addressed those concerns Saturday.
"We did what we had to do professionally, and we will continue to do that," he said. "We knew what we needed to do. I said from the very beginning -- we will protect the integrity of this case. And we did that. I think a lot of people realize that."
WATCH | Idaho authorities update public after college murder suspect's arrest
The victims' families and the Moscow community expressed relief at the news of an arrest after being on edge for more than six weeks.
"I think there's some closure there," Fry said. "And it always feels good to give people closure and to help them heal a little bit."
CNN contributed to this post.