Prosecutors say those specks of DNA tell the story of what happened at Steve Tauzer's house the night he died.
It began with a fight in Tauzer's bedroom that moved into the garage and ended with Tauzer unconscious on the floor. That's when, according to prosecutors, Chris Hillis decided to kill him.
"[He] proceeded to stab him to death by stabbing him multiple times in the temples and obviously in the brain," says prosecutor Dave Druliner.
"Maybe this is Chris Hillis' way of saying, 'You think you know what's best,' and he goes right for the brain," adds prosecutor Mike Farrell.
"I've proclaimed my innocence from Day One," says Hillis. "They come out in the paper and saying all this stuff. That's why I've hired the best attorney I can afford. I don't know what else to do."
If Hillis is found guilty of first degree murder at trial, he will face a sentence of 25 years to life. Second degree: 15 years to life.
What if he's convicted? "The nightmare continues," says Hillis. "The nightmare will continue."
On Oct. 7, 2003, Chris Hillis stunned everyone with his announcement.
After a year of claiming his innocence, Hillis admitted to killing Tauzer - pleading guilty to voluntary manslaughter. Hillis, who is sentenced to 12 years, will now go to state prison.
"Any parent can understand what could cause you to break, but you can't condone it," says Hillis' lawyer, Kyle Humphrey.
"It is almost like it didn't happen," says Hillis. "It's easy to get into denial. In fact, it's the easiest way to deal with it."
In an exclusive 48 Hours interview, just hours before he pleaded guilty, Chris Hillis told us the story of what happened the night he killed Steve Tauzer.
"I don't want to remember a lot of what happened, but that Friday night, it was late. I remember buying two cans of beer. I sat in my car outside the cemetery and drank some beer," says Hillis.
Hillis says he had been doing that frequently since his son Lance, 22, died in the violent car accident only four weeks earlier. He admits he was also taking Valium to deal with the death.
As he drove home Saturday morning, sometime after 1 a.m., he says he saw lights on at Tauzer's home: "I wanted some answers, I think, also to be real frank. And this was maybe an opportunity to get those. I knocked on the door."
Hillis says Tauzer, wearing only boxer shorts and a T-shirt, invited him in. He remembers having a beer with Tauzer, but says the conversation quickly turned ugly.
He says he was set off after seeing Lance's picture on Tauzer's counter. "I just broke down. Why his picture was on the counter, I have no idea," says Hillis, referring to Lance's college ID that Tauzer had collected, along with other belongings, from Lance's last rehab clinic.
"I'm looking at this picture of my son, and I asked him, 'Why wouldn't you leave my son alone?' And his response was that he loved Lance. And I lost it at a certain point ... I remember wrestling in the kitchen. I got pretty vicious at that point."
Hillis says he can't remember how both men ended up in the garage. He says he also doesn't remember stabbing Tauzer in the attack.
"I remember, in the garage, falling to the ground. And I thought I was punching him," says Hillis. "And apparently I wasn't."
So what does Hillis say that Tauzer did to provoke his homicidal rage?
"I'm not gonna share that," says Hillis. "I'm just … I don't want to go there."
As part of his plea bargain, Hillis was forced to reveal to prosecutors what he says pushed him to his breaking point. "He said the wrong thing … He says it was consensual ... I went after him," he told Druliner.
Hillis killed Tauzer because he believed Tauzer was sexually involved with his son, Lance. But prosecutors say the sexual relationship may have been only in his mind.
"It's rumor and innuendo, based on no facts whatsoever," says Druliner.
"I think most people thought Chris Hillis was guilty here. He goes to prison; he does his time," says columnist Herb Benham. "But Tauzer got between a father and his son. So I would think that most people would think that it ended the way it should've ended."
"Steve Tauzer, as far as we know, had good motives," says Farrell. "And despite what Chris Hillis thought, either accurately or inaccurately, for that, Steve Tauzer did not deserve to die."
Chris Hillis will spend at least nine years in prison before he is eligible for parole.
Is he sorry that Steve Tauzer is dead?
"Yeah. I get no pleasure out of that. It's brought nothing but misery to everyone," says Hillis.
As part of his plea bargain, Chris Hillis waived his right to appeal his conviction.
Since 48 Hours first aired this broadcast in January, Hillis has been serving his sentence at a California state prison just over an hour's drive from his home.
He's been teaching inmates who are about to be released how to adjust to the outside world, and he helps them with drug rehabilitation. His wife, Pam, visits once a week.
Hillis' family says he never shared his secret with them about killing Steve Tauzer -- and that he maintained his innocence right up until his stunning reversal.
In the Bakersfield's courthouse, there's a plaque in memory of Steve Tauzer, and there's talk of naming a building after him.