Speaker 1: what they're leaving out repeatedly is where this DNA started. Where did the chain start? Well, it started in a quadruple homicide at a crime scene.

Speaker 2: Two days of explosive hearings in the murder case of four Idaho college students who prosecutors say were brutally stabbed to death by this man, Brian Koberger. His attorney is trying to paint the murder investigation as flawed and shrouded in secrecy, all in an effort to get key evidence thrown

Speaker 3: out. You're being led down this path to say there's a real investigation when there wasn't a real investigation. You don't find probable cause on that.

Speaker 2: The now 30 year old is facing the death penalty charged with brutally murdering Kayleigh Gonsalves, Madison Mogan, Zanna Kernodle and Ethan Chapin in an off campus home in November of 2022. It's a case that gripped the

Speaker 4: nation ever since. It's a major break in the murder of four Idaho college students. The arrest of a 28 year old man in Pennsylvania in connection with the brutal murders of four University of Idaho students. Prosecutors say

Speaker 2: surveillance footage, cell phone records and DNA evidence link Koberger to the murders. The linchpin Koberger's DNA. We're not just talking about his

Speaker 1: DNA happened to be found in a dresser drawer or something. It was found on a knife sheath where four people were killed by a knife. This is as crime

Speaker 2: scene as it gets. But Koberger's attorneys arguing to have that crucial DNA evidence dismissed, claiming it was unlawfully obtained using public

Speaker 3: genealogy websites. If you can upload one of these profiles for $12 and find out all kinds of information. How is that not a Fourth Amendment issue that was done twice without a warrant in this case, the Fourth Amendment protects

Speaker 5: against illegal search and seizure. And what the defense is arguing here is that law enforcement used inappropriate techniques that they used in gathering DNA and then using it in a genetic genealogy database to what they argue was against policies for that database. Koberger's attorneys also

Speaker 2: arguing that authorities violated the law when they used a garbage collector to retrieve trash from the Koberger family's gated neighborhood in Pennsylvania without a warrant. The FBI using the garbage to make the DNA

Speaker 3: match. I think it is different when you have the FBI telling the trash man

Speaker 5: what to do. Oftentimes a sample of DNA that has been discarded. That's what the courts call an abandonment sample that you don't have an expectation of privacy for a pizza crust you throw out or a water bottle that you drink from

Speaker 2: and throw out. But prosecutors arguing all facets of this investigation, including the DNA and the use of public genealogy databases were done properly.

Speaker 1: The individuals who are utilizing these databases and we're talking about millions of them are willingly sharing their information with each other. The issue is that no one sharing this information with millions of other people could have a reasonable expectation of privacy based on the

Speaker 5: judge's responses to the defense's arguments. It's unlikely that this evidence does get suppressed, meaning not shown to the jury at trial. If it is suppressed, then prosecutors would have to lean on other forms of evidence. The

Speaker 2: defense also questioning the credibility of a surviving roommate. In an affidavit, the roommate recalled being in the home and frozen, seeing a man wearing black clothes and a mask walk past her. This is one of two

Speaker 6: roommates who survived and this is the roommate who gave police a lot of information. She described the killer who she saw, the man who was in the house, as being a tall white male with bushy eyebrows and that fits the description of Brian Kober. So the defense is now trying to pull apart her credibility.

Speaker 3: This witness has claimed that she's not sure what she heard or saw was real or whether it's it was at a dream. There's further statements from that witness in that police interview that said that she had had too much to drink and

Speaker 5: couldn't remember. The surviving roommate gave statements to law enforcement but the defense is trying to argue was not necessarily accurate. They may have been intoxicated or sleepy or may have seen things that might not have fit exactly perfectly for what law enforcement then articulated to the judge. After Kober's

Speaker 2: arrest, officials in the region began to investigate any possible connection to past crimes like a home invasion in Pullman, Washington, 10 miles from where the murders happened. A woman in this case says a massed assailant broke into her home holding a knife. Body camera footage obtained by ABC News shows

Speaker 7: police responding. I heard my door open and I looked over and someone was wearing a ski mask and had a knife and so I like kicked out of their stomach and screamed super loud and they like flew back into my closet and then ran

Speaker 2: out my door and up the stairs. And according to the police report, the woman describing him as 53 to 55 Kober is six ft tall. After his arrest, Kober became a person of interest for a time in that case. But police say he's no longer a person of interest and the case remains unsolved. The defense

Speaker 5: wants to raise that issue and attempt to point the finger at an alternative suspect that if there are similar crimes in the area or suspects out there other than Brian Kober committing similar crimes and that the jury should contemplate that in believing that Brian Kober is not guilty of these

Speaker 2: charges. Kayleigh Gonzalez's parents have been at nearly every one of Brian Kober's hearings, but they weren't allowed into the courtroom for this one. They had to watch from a court live stream. They want to be there for

Speaker 6: Kayleigh. They are fighting on her behalf. They believe that Brian Kober er is guilty. They want him to get the death penalty and they want all of this to be opened up. They want the world to see what's going on so it cannot be appealed at some point. They don't want evidence tossed out. They sat down with

Speaker 2: me last year talking about how their daughter was found. It's my understanding. Kayleigh was kind of sitting up. Yes. I had fought.

Speaker 8: Yeah. And the way that that room's put together. If you come through that door, you can't get out of that room. You know, the headboard was up against the

Speaker 9: wall. The side where Kayleigh was on was up against the wall. And if you can imagine Kayleigh in an upright sort of position up in the corner slumped. I

Speaker 2: mean, she was trapped. Kayleigh was one of the four tight knit college friends killed in that off campus home on King Road in Moscow, Idaho. It all began the night of November 12, 2022. Kayleigh and Maddie, newly 21 and lifelong best friends, went to a popular campus bar around 10 p.m. This video appears to be the last time they were seen alive before turning in for the night. Authorities say their roommate Xana and her boyfriend Ethan, both 20 were at a fraternity party earlier that same night, arriving home around 1 45 a.m. There's three stories to the house. Kayleigh and Maddie were together in Maddie's room on the third floor. Kayleigh's dog Murphy was alone in Kayleigh's bedroom just down the hall. Ethan was staying over that night in Xana's room, which was on the second floor. One of the other roommates in the house also on the second floor and one in a bedroom on the first floor.

Speaker 10: Everything was so normal in that home on King Road. Nobody could have imagined it was about to become a house of horror.

Speaker 2: Police responding to a 911 call just before noon, hours after law

Speaker 11: enforcement say the murders happened. When the lead sergeant goes into the house, he later told people how the high smell of blood rose up in his

Speaker 12: nostrils and it took him back. This is a brutal crime scene. These victims were not shot.

Speaker 13: They were stabbed to death. What was baffling to police, they say, is that it didn't appear that there was any forced entry. It doesn't appear that any of the victims had been sexually assaulted. Weeks later, Coburger was arrested at

Speaker 2: his parents home in Pennsylvania.

Speaker 14: Last night, detectives arrested 28 year old Brian Christopher Coburger.

Speaker 2: Coburger had been working on his Ph. D. In criminology at Washington State University, just 10 miles across state lines from the University of Idaho, where Kayleigh, Maddie, Xana and Ethan were just starting their futures, documenting their friendship on social media.

Speaker 15: I don't wake up at night, don't see your name on my phone. So the moment's when I think that I'm better alone.

Speaker 7: Kayleigh is like the definition of sunshine. To know Kayleigh was to love

Speaker 2: Kayleigh. Kayleigh and Maddie had been best friends since sixth grade.

Speaker 15: They did absolutely everything together. First dates, first boyfriends, graduated high school. They had their first heartbreaks together. Kayleigh was 12, 13 years old. They're blasting Taylor Swift in the basement, you

Speaker 16: know, comforting each other. If I had one or two words to describe Maddie May, it would be just an angel. She just made me proud. Xana was in the

Speaker 2: same sorority as Maddie. She was dating Ethan, a freshman and also a triplet.

Speaker 17: My first impression of Ethan was he's just this huge dude that you wouldn't really approach. But as soon as you really got to know him, you realize

Speaker 2: that he's like one big teddy bear. As the victim's family and friends wait for the judge to rule on this week's hearings, Coburger's jury trial is

Speaker 6: slated to begin in August. It's gonna be tough on the family members. It always is in any murder case. But this one is unique that you've got the world's attention. But for these families, they say they just want justice.