This story previously aired Sept. 28, 2013. It was updated on May 17, 2014.
(CBS News) "The wheels of justice turn slowly. I've never covered a story quite like this. "48 Hours" first started working on this cold case eight years ago and we couldn't let it go. It's hard to imagine it would take more than three decades to find the killer ... and bring him to trial." - "48 Hours" correspondent Troy Roberts
"Thirty-two years. Unbelievable. And that's why I want it over with. I want to have a little peace before I die," said Sabrina Gonsalves' mother, Kim.
Kim and George Gonsalves weren't sure they'd live to see the day.
"It's a scab on your heart, and it just keeps getting pulled off and you bleed again," Kim told "48 Hours". "And again and you just don't know how much you can keep going."
"It is so much worse when someone is killed instead of dying a natural death. But it is also worse to have a murder unsolved," said Andrea Gonsalves Rosenstein, who, over the decades has remained devoted to keeping her baby sister's memory alive.
"She loved kids. She loved being with kids, working with kids. She loved medicine. She wanted to be a physical therapist," Rosenstein told Roberts.
"She was such a good person and so innocent and so sweet and so wonderful," she continued in tears.
Rosenstein named her first born Sabrina. And after having her third child, she decided to adopt three more.
"... she wanted to have six kids," Rosenstein said of her sister, "and I did it ... for her ... with the thought that I'm having the family that she didn't get to have."
"I also wanted to keep horses in my life. And introduce them to my children and let them know that this is something that I did with Sabrina with great joy and fun," she said. "She's still with us. I feel like her spirit is still with us."
Back in the summer of 1980, Rosenstein was already attending the University of California at Davis when her sister moved in with her. Sabrina was excited to begin her own college career. That summer, Sabrina met John Riggins while working for the town's recreation department.
"He was really her first boyfriend. And she fell in love with him," Rosenstein said. "John was so much fun ... He was funny and lighthearted and he loved sports. ... they were perfect together."
John had been a popular high school athlete in Davis. But he stood out for another reason, as well.
"When he was much younger he had this mop of red hair that ... got a lot of attention, Roberts commented to Kate Riggins.
"Even as a toddler people came up and touched his head all the time. And it was almost like bringing good luck or something," she said. "And then ... if there was a sports photographer, John's picture was in there."
Kate and Dr. Richard Riggins, an orthopedic surgeon, were proud of their son. John was considering following in his father's footsteps.
"Do you ever think now about what kind of man your son would've become?" Roberts asked Dr. Riggins. "He would've been 51 years old now."
"Since he was murdered, I haven't given much thought to what he would've been as an adult. I - I just always left him there as a freshman at UC Davis. ...he's still been 18 years old and I've never really pushed it beyond that," said Dr. Riggins said choking up.
The night of Dec. 20, 1980, Sabrina and John, both 18, were expected at a surprise party for Andrea's 22nd birthday. But they never showed up -- and never called.
"I woke up first thing in the morning; it was like, six in the morning ... and then I knew something really bad had happened, because she would've never not come home," Rosenstein said of her sister.
"It was out of character?" Roberts asked.
"Oh my God ... I knew where she was all the time. She knew where I was all the time. We didn't do that," Rosenstein replied.
"When you realized he hadn't come home," Roberts asked Kate Riggins, "what was going through your mind?"
"It was so foggy that night. You could not see anything," she recalled.
"And we just got out and drove in increasing circles, looking in the ditches, and looking for some evidence of an auto accident," Dr. Riggins said. "The possibility that they'd been kidnapped and murdered was not even considered. I mean, we didn't want to consider that."
Sabrina and John had been missing for 36 hours when police found the Riggins' family van abandoned about 30 miles east of Davis in Sacramento County.
"There was nothing in the van to indicate that something horrible had happened at that point. We were hoping to find them alive," said former Det. Carol Daly.
But a few hours later, Det. Daly received the call that the bodies had been found just under a mile away, discarded in a ravine.
"It was so traumatic; to see them and their bodies disposed of the way that they were," Det. Daly said. "I've just never been able to forget it."
"It was sickening," Det. Daly said of the brutal slaying. "The horrificness of what we were seeing and what they must have gone through. They had duct tape around their eyes and around their mouth. ... Looking at them, we knew their throats had been cut. And they were dumped. Just like trash."
There were signs that Sabrina had been sexually assaulted. John had a head injury suggesting he'd fought to protect her.
"Eighteen, they're just children," Det. Daly said. "How are the parents going to be able to handle all this?"
"I understand that you wake up in the middle of the night thinking of your son?" Roberts asked John's parents.
"He comes into our thoughts. And like a nightmare, a small nightmare most nights," Kate Riggins replied.
"I can't ever see getting rid of that haunting figures that I see every now and then, of their bodies in the ditch. That's never gonna go away," Dr. Riggins said, getting emotional at the memory.
"32 years they have been dead," Rosenstein said. "How many people, how many years, how much effort does it take to put one horrible person away for life?"
The case became known as the "sweetheart murders." Investigators from two counties mobilized to hunt down this sadistic killer.
But they had no idea just how difficult that would be.
Serial killer on the loose?
As the town of Davis said goodbye to the two sweethearts, their chilling murders had police fearing a serial killer could be on the loose.
"When you cut somebody's throat with a knife ... you either have to be pretty desperate or you have to be pretty cold-blooded I would say," said Investigator Ron Garverick with the Sacramento District Attorney's Office. "The suspect did some planning. He came there with a sharp knife or some other weapon. He brought some tape with him."
Police received hundreds of tips. They even released acomposite sketch of a suspicious man spotted in the area.
"This is the kind of rough brush that the bodies were found in?" Roberts asked Garverick. "It was just by luck that the officers found the bodies, right?"
"Yeah," the investigator replied, as they stood near the site where the bodies were discovered. "Because the roadway was one elevation and the ravine was probably you know eight to 10 feet down. And looking straight across, you wouldn't see it. ... So somebody had to be somewhat familiar with the area."
But the investigation went nowhere and the trail went cold. Year after year, the lack of answers only added to the families' pain.
"I despaired that we would never find the person that killed them," Kim Gonsalves said. "I would say the first year was really bad, really devastating. I think for five years I really was fragile. That's the best way to put it, very fragile."
Six years passed and then a tip led police to revisit another double murder that happened around the same time to see if there was any connection.
KOVR TV report: "The body of 22-year-old Craig Miller was found near bass lake in Eldorado County, shot three times in the head. His girlfriend, Mary Beth Sowers, is still missing tonight and feared dead by lawmen ..."
Like John and Sabrina, this college couple was abducted from a public place, killed execution-style and then dumped around the Sacramento area.
But in this case, police quickly made an arrest and got a conviction.
The killer was Gerald Gallego, a violent sexual predator. But on the night John and Sabrina were killed, he had an airtight alibi: he was already in jail. And that's why police, looking at the sweethearts case years later, arrived at an unusual theory: that John and Sabrina's murder was a copy cat crime, committed by Gallego's friends to try to clear him.
"Well then it couldn't be Gerald that's the murderer because of the fact that the killer's still out there," Garverick explained. "Hundreds if not thousands of hours went in to prove that theory. And arrests were made behind it."
In 1989, nine years after the sweetheart murders, police arrested David Hunt, Gallego's half brother, who also had a criminal past. Believing he had help, they rounded up Hunt's wife, Sue Ellen, and his partners in crime, Richard Thompson and Doug Lainer. They became known as the Hunt group. All four were charged with the murders of John and Sabrina.
"I was so angry for being accused of something like that!" Lainer told Roberts.
"Gotta let that anger go, brother," advised Hunt.
David Hunt and Doug Lainer maintain their innocence to this day.
"Did you kill Sabrina and John?" Roberts asked Hunt.
"No," he replied.
"Did your brother mastermind these killings?" Roberts asked.
"No. by this time my brother was dead to me," said Hunt.
Both men admit they were drug addicts and thieves, but insist they would never commit murder.
"Both of you were described as sophisticated, savvy desperados," Roberts commented.
"Well, I wouldn't go that far," Hunt said with a laugh.
"I'm a dumb little criminal is what I was, doing dumb little criminal things," added Lainer.
Those "dumb things" Lainer did included stealing bed sheets from motels. But this time - even with no physical evidence -- he and the other members of the Hunt group were facing the death penalty.
"It's ludicrous! Think about it," Lainer exclaimed.
"So this wasn't designed to free Gerald?" Roberts asked Lainer.
His reply: "You know what I have to say about Gerald?" Lainer gestured, giving the finger.
"I feel the same way," said Hunt.
On the eve of the Hunt group's trial, there was a stunning development. It involved that birthday gift Sabrina had intended to give her sister Andrea: a blanket. Apparently, the killer had unwrapped it and left semen stains that went unnoticed for years.
Those stains could now be tested for DNA, a forensic tool that didn't exist at the time of the murders. Police asked for blood samples from the accused.
"What did your attorney advise you to do?" Roberts asked Hunt.
"They came to me and actually ... they told me that the bottom line is, if you did this, or have knowledge of it, don't let 'em do this," he replied.
Asked why, Hunt said, "Because it'll send you to death row. Now my response was very simple. ' Let's get it done. How soon?'"
Lainer, too, was certain the DNA would prove his innocence. "I ran down the hall tap dancing. I was so ecstatic, knowing case is over now, we got 'em. 'Cause the whole thing was a setup to begin with. Now they couldn't get away with it," he told Roberts.
And as they predicted, the DNA on the blanket did not match any of the men in the Hunt group. So in January 1993, all the charges were dropped.
By then, David Hunt and his co-defendants had spent three years in jail.
"They framed me and almost got away with it. I could be going to the gas chamber today and that's an outrage!" Lainer said after his release.
Investigators were back to square one.
"I thought it was over with. And I was doing my best to get it buried and to get on with my life," said Dr. Riggins.
"To not know who did it and why is something you never stop thinking about," Rosenstein said. "Is the person out there killing other people?"
A DNA hit
After their son, John, was murdered, Dr. Richard Riggins and his wife, Kate, still had two younger children to raise; son Robert, and daughter Carrie.
"Why did you move from Davis?" Roberts asked Dr. Riggins.
"I couldn't stand all the memories. And when you went to the hospital to go to work, you passed the morgue every day," he replied. "And that was just too much for me."
The lack of an arrest made it even harder. But by 2002, DNA science had advanced even more. The state crime lab was now routinely comparing DNA from cold cases to that of convicted criminals stored in a new database. When they uploaded the DNA from those semen stains on the blanket, incredibly, there was a hit. Scientists called it a "one-in-240 trillion match."
"... a DNA match had been found," Garverick explained. "And that it belonged to a suspect who was currently in prison up in the state of Washington."
The suspect's name was Richard Hirschfield. Local investigators had never heard of him, but they soon learned he had a very dark past.
"Richard Hirschfield is a serial sexual predator," prosecutor Dawn Bladet told Roberts. "He has victimized children and adults through his lifetime ... I just think he is a vile human being. And he is the worst of the worst."
At the time of the DNA hit, then 53-year-old Hirschfield was in prison for molesting two little girls. Many years earlier, in 1975, he'd been convicted of rape in northern California.
In 2006, "48 Hours" spoke to his California victims -- two sisters, Marge and Michelle, who didn't want their last names used.
"We're lucky to be alive, really," Marge said. "He had the gun. It had a silencer on it. No one would have heard."
They were 22 and 16 at the time he entered their apartment, demanding money. When they told him they had none, "he was mad. 'All right then, who wants to be raped.' And then my sister offered herself instead of me," said Michelle.
"Anybody in my position would have done the same thing. She was my little sister," said Marge.
"What are you thinking about right now?" Roberts asked Michelle.
"How it affected my life and made me fearful," she replied in tears.
Hirschfield served only five years in prison for that crime. He was paroled in July 1980.
"He was able to convince people in the corrections field that ... he was not a danger," said Bladet.
Five months later, John and Sabrina were murdered.
"If only he woulda stayed in prison a little bit longer ... if only he hadn't come to Davis ... it just brought it all back again," said Sabrina's sister, Andrea Gonsalves Rosenstein.
This time, Hirschfield wasn't going anywhere. He remained behind bars in Washington in the child molestation case while California investigators cemented theirs.
"There's a lot of work that goes on after the cold hit. Some people think, you hear the DNA match, we have the suspect, that's the end of the story," Bladet explained. "This person came out of the blue. ... did they have any connection to Sacramento? ... Did they know anyone in Davis?"
The answer to both questions was yes. Hirschfield once had friends in Davis who lived across the street from the condo Andrea and Sabrina shared. And that's where authorities believe Sabrina and John were abducted.
"So this was five days before Christmas? Most of the students had gone home?" Roberts asked Garverick.
"Yes," he replied. "Like every university town, they start their break. And this place is pretty vacant."
"And because this place was deserted, no one could hear their cries if they were abducted in the complex?" Roberts asked.
"It's that, and that night was extremely foggy so your visibility's way down," said Garverick.
Asked if she believes Hirschfield was stalking Sabrina, Bladet told Roberts, "Yes ... I think Sabrina was selected because of her looks; she was very attractive. And I don't think it was a coincidence that he happened upon her."
Investigators also learned that Richard Hirschfield had a brother, Joseph, who was living in a house near Sacramento at the time of the murders. It's just a few miles from where the bodies were dumped.
"The assignment that my partner and I had was to go talk to him and ask him what he knew about his brother, Richard, in 1980," Garverick explained, "and we let him know that Richard's a suspect in two murders from 1980."
"He was a little nervous throughout the interview, but my partner tells me, 'When you said DNA, he started shaking,'" Garverick continued. "We didn't know what to think."
The next day, Joseph Hirschfield got into his car and committed suicide by carbon monoxide poisoning.
The note he left behind was a bombshell:
I have been living with this horror for 20 years. Richard did commit those murders, but I was there. I didn't kill anyone, but my DNA is still there.
Joseph's DNA was never found in the Riggins' van. And no one knows exactly what role he played in the murders. But even with strong evidence -- Richard's DNA and Joseph's suicide note -- the case was moving at a snail's pace.
Asked why it took 10 years to bring the case to trial, Bladet told Roberts, "capideath penalty is on the table, it typically takes longer. Obviously the stakes are higher. ... The sheer volume of materials was overwhelming and daunting."
The case had over 200,000 pages of discovery. Hirschfield's defense team would file more than 200 motions and be granted many delays.
"And every delay was to his benefit, not ours," Rosenstein said. "The victims should have a right, too. We have a right to get this done. ... It cost us, the state of California, the taxpayer, millions of dollars."
"Is the system broken?" Roberts asked Rosenstein.
"You know what? I really do believe there is something horribly wrong with it," she replied.
And time took its toll. Sabrina and Andrea's father, George, received a devastating diagnosis: he had Alzheimer's.
"He wanted to be at the trial; he wanted to see justice done to the man who murdered his baby," Rosenstein said. "And all he kept saying is,
'Is it gonna be fast enough? Am I gonna be able to be there? And I gonna be able to testify?'"
Finally, in September 2012, 10 years after the DNA hit - and almost 32 years after the notorious murders - the trial of Richard Hirschfield was set to begin.
The trial of Richard Hirschfield
When his capital murder trial finally begins, the now- 63-year-old Richard Hirschfield enters court in a wheelchair, barely resembling the menacing figure he once was.
"Why did you want to be in the courtroom to hear all that testimony -some of it graphic in nature?" Roberts asked Andrea Rosenstein.
"It's a matter of needing to be there," Sabrina's sister replied. "I wanted the jury to know that we were there, to know that we cared."
"Sabrina was also encompassed, her face, in duct tape" prosecutor Bladet told the court in her opening statement. "...it covered her eyes, her nose, and her mouth."
"These were not bodies on a slab, these were real people," an emotional Rosenstein told Roberts.
The prosecution has a powerful case against Hirschfield, starting with the DNA match.
"You cannot make somebody's DNA appear on evidence," Bladet told jurors.
"Mr. Hirschfield is wrongfully accused," lead defense attorney Linda Parisi told the court.
Parisi does not deny it's Hirschfield's DNA on the blanket, but insists it could have gotten there some other way.
"His DNA just magically appeared on its own on this blanket?" Roberts asked.
"I don't think it magically appeared at all," Parisi replied. "...the van was open. ... during that period of time Mr. Hirschfield was in transition in terms of having a residence ... And in fact a person was seen sleeping in the van."
"That just makes no sense whatsoever," Bladet told Roberts. "... that someone who is a sexual predator ... happened upon a van that just was used in a double homicide ... and somehow deposited his semen."
Prosecutor Dawn Bladet points out Sabrina's DNA was found mixed in with Hirschfield's -- evidence of a sexual assault. "... that tells you that they were there at the same time," she said.
Then there's Joseph Hirschfield's suicide note implicating his brother, Richard, in the murders. Over defense objections, the jury hears from Joseph's widow, Lana.
"I then called Joseph to tell him that some detectives had been to our home and that they wanted to question him," Lana Hirshfield testified.
It was 2002, shortly after the DNA hit, when investigators came calling. Lana sent them to Joseph's workplace.
Dawn Bladet: And when he came home, can you describe how he was acting?
Lana Hirshfield: He was very upset. And he was very red-faced.
Dawn Bladet : Was that normal for him?
Lana Hirshfield: No, he was actually a very calm person
The next night, Lana discovered her husband's body in his car -- along with that suicide note.
"I have been living with this horror for 20 years. I was there. My DNA is there." The prosecutor reads only part of that note to the jury - because the defense has succeeded in getting the most incriminating part redacted. What the jury doesn't hear or see is this part of the note: "Richard did commit those murders" and "I didn't kill anyone."
"We didn't believe the suicide note was relevant or reliable," Parisi told Roberts. "When people are planning their own death ... it is not at all uncommon for them to rewrite history."
The prosecutor wants the jury to have no doubt which brother was capable of committing the murders. Judge Michael Sweet allows testimony from Richard Hirschfield's other victims because of similarities in the crimes. Marge, the woman Hirschfield raped in 1975, is eager to help put him away for good.
"I think we've wasted enough time, enough energy, enough years. I think he should get the death penalty," Marge told "48 Hours" outside of the courtroom.
Marge takes the stand and confronts her rapist for the second time in 37 years:
Marge: He took off all his clothes - everything but his T-shirt. And then he sat on the couch.
Dawn Bladet: And where was the gun?
Marge: He was still holding it.
Dawn Bladet: Was he pointing it anywhere?
Marge: At my head. I could feel it on my temple.
Marge's words are chilling as she identifies her attacker:
Dawn Bladet: Do you recognize the man in that photo?
Marge: Yes I do.
Dawn Bladet: And who is that?
Marge: Richard Joseph Hirschfield.
Dawn Bladet: And how do you know him?
Marge: I will never forget him. He's the man that raped me in 1975.
Faced with such damaging testimony, defense attorney Parisi decides her best strategy is to point the finger right back at the Hunt group - in spite of the DNA pointing elsewhere.
"This group was exonerated years ago," Roberts pointed out to Parisi.
"They were not exonerated," she said. "... it was not where there was a finding that they were not involved. It was a finding that their DNA did not match with what was found on the blanket."
The defense's star witness is a paid police informant who, at one point, committed robberies with David Hunt.
In 1987, detectives sent Ray Gonzales to meet with Hunt associate Richard Thompson to try to get him to implicate David Hunt in the murders.
Linda Parisi: Did he tell you about his participation in these murders?
Ray Gonzales: Yes he did.
Linda Parisi: And what did he tell you?
Ray Gonzales: We talked and he indicated that, you know, that him and David Hunt were involved with it.
Linda Parisi: You ask him some questions about "that guy putting up a struggle." Do you have a recollection of that conversation?
Ray Gonzales: Are you talking about ... John Riggins?
Linda Parisi: Yes.
Ray Gonzales: Yes he put up a struggle. And David settled him down real quick. He had - apparently he had hit him with some sort of object or something and settled him down real quick.
Although he was supposed to be secretly recording this meeting with Thompson, Gonzales failed to get any of this alleged confession on tape.
"You asked me a lot of things I don't remember. Some things I just don't recall," Gonzales testified.
And maybe that's because he'd had 16 beers that night.
Dawn Bladet: "How many beers did you have?
Ray Gonzales: I don't recall, couple, two, three beers.
Dawn Bladet: Do you recall testifying - previously in 1992, that you had about seven in the motel room and another nine in the bar?
Ray Gonzales: I don't recall that.
Dawn Bladet: If you had testified to that, would you have been testifying truthfully?
Ray Gonzales: Uh-huh. But I don't recall."
"Ray Gonzales is not an uncommon type of witness that we see," Bladet told Roberts. "He's gotten cash for snitching on various people since he was a teenager."
While Gonzales spent a great deal of time on the stand saying he couldn't remember, for David Hunt, this is one case he'd rather forget.
"How does it feel right now with the Hunt group back in the news?" Roberts asked Hunt.
"Well, it sucks," he said with a laugh. "This was such an ugly thing from the beginning, just a straight ugly horrible story ...I'm just tired of it; I've been burned out on it for a long time."
In the end, the defense never called on David Hunt to testify. He was greatly relieved. Hunt says he left his criminal life behind long ago and found redemption through his Christian faith.
"I ran into a God that understood me so much better than I did. We had a lot of long talks," Hunt said. "I've done my best to straighten my life out. That's all I can do."
"I understand that you're very, very ill," said Roberts.
"I have stage four cancer, pancreatic cancer," Hunt explained. "And I probably won't last that long."
Hunt is hoping to live to see his name cleared once and for all with a guilty verdict against Hirschfield.
As the case draws to a close, the victims' families addressed the court.
"Our John and Sabrina were simply destroyed and left to die," said Kate Riggins.
Sabrina and John's families are hoping they can help make that verdict happen.
"I am physically sickened and enraged when I think of the terror, pain and horror they must have felt as they died in a ditch," Rosenstein told the court.
The case against Richard Hirschfield is about to be handed to the jury and the stakes couldn't be any higher.
Asked if he deserves deaths, Dr. and Mrs. Riggins reply without hesitation. "Absolutely."
Prosecutor Dawn Bladet delivers an emotional closing argument.
"I struggle because these crimes are so incomprehensible. They are so horrific that none of these words really capture the kind of evil that happened that night," she said, pointing to Hirschfield.
Bladet reminds the jury of the strong physical evidence.
"That DNA on that blanket is sex. Semen is sex. This is a sexual crime," she said.
To cast doubt on the DNA, defense attorney Linda Parisi suggests the blanket could have been contaminated through careless handling by investigators.
"They put it in this bag," she said, holding up the tattered evidence bag. "We didn't make up this bag. This bag isn't - a stage prop. This bag is the for real bag."
Bladet doesn't mince words as she pounces on that other defense theory of how Hirschfield's DNA might have gotten on that blanket: "So now what do they suggest to you? He's the random masturbator ... just happens to have the urge to relieve himself on an item inside that van?"
It is Nov. 5, 2012. The jury of seven men and five women deliberates less than three hours.
The verdict: guilty in the murders of both John and Sabrina. It is a huge relief for the families.
"We won't be able to bring him back, nor Sabrina but we hope this is the beginning of justice for this horrendous case," Kate Riggins told reporters following the verdict.
The jury reconvenes three weeks later for sentencing, to decide whether Richard Hirschfield deserves the death penalty.
"Visualizing the way he died, you know, wrapped up in tape, throat cut, thrown in a ditch, trying to breathe ... knowing he's dying and (chokes up) excuse me," Dr. Richard Riggins told the court.
A private man, Dr. Richard Riggins has never so publicly shared the deep pain of his loss.
"I wasn't there. And there was nothing I could do. So I'd failed in my biggest duty to him," he continued.
And there is more gut-wrenching testimony from Sabrina's mother.
"This is really hard for me. I don't like to cry in front of other people. And I really don't like to cry in front of him," Kim Gonsalves said referring to Hirschfield.
"You have a lot of anger and you have to live with it for 32 years," said prosecutor Bladet.
"It ripped my heart out and it killed me. Or I wish it had. I wish it had been me," Kim Gonsalves said in tears. "You love your kids and you want the best for them their whole life."
While the prosecutor pushes for the death penalty, defense attorney Parisi hopes the jury will show mercy and spare Hirschfield's life.
"Mr. Hirschfield didn't have an easy life. Some will say he didn't have a chance," Parisi told the court.
Parisi told Roberts, "His mother was raped by Mr. Hirschfield's father ... His father ... was a very cruel man, physically, emotionally abusive."
A lot of people have horrendous childhoods and they do not go out and murder and torture and become pedophiles," Kim Gonsalves told "48 Hours".
And Parisi believes there's another reason her client cannot help being prone to violence. Defense witness Dr. Douglas Tucker has studied MRI's of Hirschfield's brain.
"These are very abnormal scans. This constitutes brain damage," Dr. Tucker told the court, showing the scans. "This is a serious brain abnormality in an area of the brain that's involved with emotional processing and control over behavior."
Dawn Bladet: OK, you're not saying that he can't exercise free will?
Dr. Douglas Tucker: No, I'm not saying that.
Dawn Bladet: Not saying that he's not capable of making decisions about what is right and what is wrong?
Dr. Douglas Tucker: I'm not saying that.
Dawn Bladet: You're not even saying that he's mentally ill, correct?
Dr. Douglas Tucker: I'm not saying that.
The case goes to the jury for the second time.
"He chose death over life for John and Sabrina. He chose murder over mercy for his victims that day," Bladet said in her closing.
"This is the time to punish. But it's time for the killing to stop," Parisi told jurors.
This time, they deliberate for only two hours. The sentence: death.
As Judge Michael Sweet later upholds the death sentence, he directly addresses Sabrina and John's families. It is Jan. 25, 2013, 32 years after the murders.
"You have endured so much. The tortured history of this case must have taken away any hope you had that the person responsible for these acts would be discovered and held to answer," he said. "My sincere and deep-felt apologies for the tragedies you have suffered."
"Richard Hirschfield is evil. He is a very evil man this is a very appropriate penalty if you think of Hirschfield's contribution to society ... humiliation pain and death," Dr. Riggins said.
"I can't believe it. It's over. I'm so relieved. I'm so happy," Andrea Rosenstein said following the sentencing.
And the families are forever grateful to the prosecutor who finally closed this case -- a case she herself will never forget.
"Did you make a silent promise to these young victims? " Roberts asked Bladet.
"More than once, yeah. Yeah. And I felt gratitude that I was able to come through for them," she replied.
"I know that you'll never forget her. But emotionally, are you free now?" Roberts asked Rosenstein.
"I'm not free, because I miss her," Sabrina's sister replied. "But, he's out of our life. ... we never have to think about him again. ... I can just miss her; I can just think about that and I'm really, we're really ready to do that," Rosenstein said with a smile.
Richard Hirschfield is currently on death row in San Quentin prison. He is appealing his conviction.
David Hunt never lived to see his name cleared; he died during the trial.
Dawn Bladet received the Sacramento County "Prosecutor of the Year" award for her work on the "sweetheart murders" case.
Journalist and author Joel Davis has written "Justice Waits", a book about the "sweetheart murders" case and has been following for the last 12 years. He was also a CBS News consultant on the case.