Produced by Deborah Grau and Gayane Keshishyan
[This story first aired on Jan. 5 2013. It was updated on July 6.]
(CBS) MIRA MESA, Calif. -- It was the early hours of March 12, 2011, when David Ditto found the lifeless body of his wife, 38-year-old Karina, and called 911:
911 Operator: Hi. Medical 323, what's the address of your emergency?
David Ditto: 7723 Canyon Point Lane ... my wife hurt herself running down the stairs ... please send an ambulance.
911 Operator: How old is she?
David Ditto: Please send an ambulance.
911 Operator: I do not want you to hang up ...
When first responders arrived at the Ditto home in Mira Mesa, a San Diego suburb, an emotional David told them his Karina had somehow fallen down the stairs and struck her head on the tile floor.
"I started asking her, 'What's wrong, what's wrong, are you OK?' 'Honey, are you OK?" Ditto told "48 Hours" correspondent Maureen Maher. "She wasn't moving, wasn't talking. So I -- I grabbed her, and held her. Lifted her into my lap. And was -- was holding her, and trying to get her to come to and she didn't respond, or didn't move at all."
Karina was rushed to the hospital, unable to breath on her own. For two days, Ditto and his family stood vigil as she clung to life.
"I was told that first day that she was brain dead," he explained in tears. "And then it was -- it was almost impossible that she would ever recover. Then, you know, the next doctor or nurse -- the next doctor would tell me, 'You know, there's-- it's still the same situation. There's -- she's not -- she's not gonna recover.'"
"It was really hard. I think at first it was just so hard for him to believe. They had their lives planned ahead. And it was just so hard to accept that this actually was happening," said Ditto's mother, Pat Doughty.
Doughty couldn't believe what had happened to Karina, the beautiful young woman who had captured her son's heart 20 years ago.
"This was the girl. This was the one that -- that was going to be his wife," she said.
It was the summer of 1993. Ditto was on college break, vacationing in Mexico. On his way to Cabo San Lucas, he stopped in the tranquil resort town of La Paz.
"I stopped to have lunch on the waterfront and I was parked in my car. Saw a pretty lady with pretty eyes and a beautiful smile. And she caught my eye," he said.
Karina was a shy 20-year-old.
"She'd smiled at me once or twice and I got up the nerve to go over and talk with her," Ditto told Maher.
"Would you describe it as love at first sight?" Maher asked.
"As close to love at first sight as you can get, I believe, yeah," he replied.
"When she was about 8 or 9 years old she'd say that she wanted to date an American," said Karina's mother, Silvia Benitez.
Benitez, the owner of a beauty salon in Mexico, knew her daughter was instantly smitten with David Ditto. She, however, was not.
"At first I didn't trust him," she told Maher. Asked why, Benitez replied, "He was too good looking and I said no, it's not possible for him to fall in love with a person like my little girl. And I asked him, 'Why her? She's Mexican and has different customs.'"
Karina spoke no English and David Ditto spoke little Spanish, but often, love has its own language. The two sparked up a long distance love affair through phone calls and letters and within a year, they married.
They first had a civil wedding in La Paz with Karina's family and then a traditional ceremony in San Diego with David's family.
"My stepdad, Bill, walked Karina down the aisle since her dad wasn't here to walk her down the aisle, and that was really special," said Ditto's sister, Maggie Cascio.
Cascio was one of Karina's bridesmaids.
"It was a beautiful wedding, it really was. The pictures -- when I look at them now, you know, I think, 'Oh, Karina, so young. My brother was so young.' I remember he had cut his hair, I think, probably, to please Karina's parents or her family more," she recalled with a laugh.
Newly married at the tender age of 21, Karina left her family, and all that was familiar, behind to start a new life with her new husband.
"I really respected the choice that she made to come up here, leave all her family, come to a new country where you don't speak the language. Not familiar with the culture," said Cascio.
Asked how Karina adjusted to life in the U.S., Ditto told Maher, "There was some difficulty. It was completely different. She was, you know, nervous and like a stranger in a strange land."
While going to school to learn English, the newlywed was completely dependent on her husband.
"He helped her a lot and kind of guided her at the beginning," Doughty explained.
Karina devoted herself to learning everything she could about life in America. She was particularly devoted to building her life with her husband.
"Karina really wanted to be a mother. That's something that she knew almost her whole life that she wanted to be a mom. And she was really good at it," said Ditto.
In 1996, they had their first child, a son. A few years later, their daughter was born.
As the couple was starting their family, Ditto was also starting his career. He took a job as a lab researcher at the University of California, San Diego.
"We were, you know, financially, just kind of starting off," Ditto explained. "... it was a little bit of a struggle. Didn't have a lot of money, but we had, you know, enough to pay the bills and, you know, have -- have food and -- and everything."
It seemed Karina was actually living the life she had always dreamed of as a little girl in Mexico ... from the perfect husband to the perfect home that David Ditto spent years saving up for.
"They had great plans for this place," Doughty explained walking through the home. "She wanted this house. She wanted this house. And David, you know, made every effort to get this house for them. And they did."
"They were just, you know, the ideal family and everybody -- everybody thought so. And just, you know, thought, 'What a wonderful family,'" added Cascio.
But appearances can be deceiving, as revealed in Karina's letters to her mother.
"... Sometimes I don't know why I married him," she wrote. "I'm in despair ..."
As Karina Ditto was fighting for her life, David Ditto was describing to first responders the events leading up to and immediately after his wife's horrifying accident.
Earlier that evening, the kids went to bed. Then, Karina and David settled in for the night to watch "Braveheart", one of Karina's favorites.
"We got our snacks, and candy, and chips, and drinks, and stuff. And we were watching the movie," said Ditto.
At some point, they paused the movie so each could use the restroom. Ditto used the bathroom downstairs and Karina went upstairs.
Ditto returned to the living room. What happened next was simply unthinkable.
"I heard the cat screech at the top of the stairs, and I heard a horrible falling, down the stairs. Just -- a really noisy, bang-bang-bang-bang, coming down the stairs. And I jumped up and ran over, and found Karina laying at the foot of the stairs. And she wasn't moving-- wasn't talking," he told Maureen Maher.
Ditto says he grabbed Karina and pulled her away from the stairs.
Kneeling by her side, he shook her. When she didn't respond, he began CPR. Finally, Karina started moving.
"But she was grabbing on me - hold -- trying to pull herself up. And I was holding her up. And -- and then she just stopped moving, she just kind of collapsed and was laying there lifeless in my arms. I didn't know what to do and I laid her back down, and I don't remember if I started doing CPR again or not. But I realized that -- I just didn't know what was happening to her," Ditto said in tears.
That is when he made that 911 call:
David Ditto: ... my wife hurt herself running down the stairs.
911 Operator: OK.
David Ditto: Can you bring an ambulance?
911 Operator: OK, are you with your wife right now?
David Ditto: I need to go get her. I need to go get her.
It was just after midnight. First responder Lisa Challender was on duty.
"We were expecting to see a fall. We were definitely not expecting to see a cardiac arrest," Challender told "48 Hours".
Karina's heart had stopped and she was covered in her own blood from a gash to the back of her head. The amount of blood surprised the experienced paramedic, but it was the location of Karina's body that immediately made her suspicious.
"The stairway was here. And the patient was over here," Challender pointed out. "So you don't fall down the stairway and then bounce around the corner."
From the blood pattern around Karina to the scratches on Ditto's face, Challender felt the scene actually suggested there had been an intense struggle and David's story didn't add up.
"He said that when he was doing CPR at one point, she had come back to and that he got the scratches on his face from that," Challender explained. "She had so much blood on her face that if he had put his mouth over her mouth, he would've had her blood on his face."
Given their concerns about David Ditto's behavior and the suspicious nature of the scene, first responders called police. But at the house that night, Ditto told them repeatedly that Karina's injuries were the result of a fall down the stairs. So police allowed him to leave the scene to be at his wife's side at the hospital. What the cops didn't know at the time is that over the years, there had been problems in the couple's marriage.
"When you fought, would it get -- verbally abusive?" Maher asked Ditto.
"There's only one time that I could recall and it was, you know, more than 10 years ago. Karina and -- and I were -- were arguing about something. And she was really upset. And she asked -- 'I just want to know one thing. I want to know if -- if I make you sick or if I'm sickening to you.' And I just said, 'Yes,'" he replied.
One of the few people who knew about the problems in David and Karina's relationship was Karina's mother, Silvia Benitez.
Karina confided in letters to her mother that David had become impossible to live with and she wanted to leave:
"... He wants to tell me what spoons I should use when it's time to eat. He wants to tell me how much water I should use to water the plants ... he punishes me with money. He takes it away for months ..." Benitez read. " ... There's times that I don't even want to speak to him, I don't want him to touch me... I have to tell him that sometimes I can't stand this situation ..."
"Would she have described you as controlling of her?" Maher asked Ditto.
"I don't think so. She had freedom to, you know, do the things that she wanted to," he replied.
"Were you strict with her about what she spent and where she spent it?" Maher asked.
"We were on a tight budget at times. And I managed the finances. So we didn't have a lot of money sometimes to spend on clothes or, you know, going out to eat and things like that," said Ditto.
"Did you make her pay you back for diapers and other goods for the kids?"
"I don't think so. I honestly don't remember for sure. I don't think so," Ditto replied.
By 2009, their marriage had reached a breaking point.
"I said, 'Well, maybe we should look into separating.' Because she was clear that she didn't want things to continue the way things were," Ditto explained.
But David Ditto wasn't about to give up on all that he had invested in his marriage and asked Karina for a second chance.
"And what did you ask for a second chance to do? What did you want another chance at?" Maher asked.
"To do the things that she said that she missed from the way things were before," Ditto replied.
According to Ditto, their relationship did improve, but he noticed a change in Karina.
"Did you feel like you were in charge in the relationship and now suddenly she was trying to be in charge?" Maher asked.
"I wouldn't say suddenly, but yeah, she was taking charge of -- of some things," said Ditto.
Taking charge and continuing to assert her independence, for the first time in 15 years, Karina got a job working at a nearby department store. She was making money and friends.
She struck up a relationship with a young co-worker named Jonathan Mota.
"She was very nice. One of the nicest people I've ever met," Mota told Maher.
"So you were friends?"
"Yes," he replied.
"Did you have a flirtatious relationship, as well?" Maher asked.
"Yes. Yes. It was flirtatious, but in, like, a fun way. You know, playful banter. Just sexual jokes, here and there. And stuff like that," said Mota.
Mota says their flirting never got physical, but it did get personal.
"Did you ever text her a particular picture of your private parts?" Maher asked Mota.
"Yes. I did," he replied.
Asked why, Mota replied, "She asked for it."
Mota also made suggestive comments on one of Karina's Facebook photos -- comments that David Ditto read.
"The comment was something like, 'How about you and me?' Or 'How about you and me, girl?' Or 'How about you and me, baby' or something like that," said Ditto.
"Did you think there was anything going on between them?" Maher asked Ditto.
"No," he replied.
But just a few months before, Silvia Benitez says Ditto worried Karina was going to leave him.
In August 2010, while visiting the family, Benitez says her son-in-law turned to her for help -- something Ditto strongly denies.
"He cried a lot and said Karina wanted to leave him. He told me that I have a lot of influence over my daughter and wanted me to speak with her and plead for her not to leave him. So I told her, 'Give him another chance, my love,'" she explained.
The next time Benitez would see her daughter was seven months later.
She says Ditto only told her that Karina had been in an accident. It wasn't until she saw with her own eyes the seriousness of the situation.
"I began to hug her, talking to her, telling her to please open her eyes," said Benitez.
After being in a coma for two days, Karina's life came to an end.
"Were you there when they took her off life support?" Maher asked Ditto.
"Yes," he replied in tears.
"Did it seem impossible to you that your healthy wife had fallen down the stairs and now she was gone?"
"From a fall?"
"It was unthinkable. Shocking, surprising," Ditto replied.
Equally shocking, however, is what David Ditto did just 15 minutes before his beloved wife was taken off life support.
With his cell phone, David took a photo of his once stunning wife, Karina. She'd been covered with paintings of her own handprints. It was for a reason says San Diego prosecutor Claudine Ruiz.
"The only reason that I could come up with for why David Ditto took that photograph was as a trophy," Ruiz told Maher.
" -- remember what he had done to her."
"That he had the final word," Maher remarked.
"He controlled her life and he controlled her death," said Ruiz.
"I know what happened that night, and I know that I didn't kill her. I know that she fell down the stairs. And she obviously hit her head, hurt her head," said David Ditto.
For veteran San Diego homicide detective JC Smith, Karina Ditto's brutally bruised body told a different story.
"Karina had many bruises all over her body and she had a laceration to the back of her head. She also had -- bruising and swelling to the front of her face, both of her eyes," Det. Smith explained.
Smith says Karina struggled violently until the bitter end -- so violent that it left marks on David Ditto.
"That was consistent with domestic violence, with a fight, with a woman scratching and fighting for her life," he said.
"Reaching up and-- and clawing?" Maureen Maher asked.
But if there was a violent struggle that night, wouldn't the commotion have woken up their 14-year-old son and 10-year-old daughter?
"Both children were upstairs sleeping. You would think that, with all the noise of a struggle, with the paramedics coming, the firefighters responded with -- with lights and siren, and bringing all their equipment and all these men coming in with equipment to work on a victim, the children never woke up. David had access to narcotics and we thought, possibly, he used the drugs on his kids," said Det. Smith.
"Did you give your children anything that night to make them sleep?" Maher asked Ditto.
"No, absolutely not," he replied.
"And what do you think about that accusation? That's a pretty strong accusation, because it clearly implies premeditation," Maher continued.
"It's -- it's baseless, like most of the insinuations and accusations," said Ditto.
By now, detectives were having a tough time buying any part of David Ditto's story.
"So these are the stairs inside the Ditto home. It shows 11 carpeted and padded stairs with a tile floor at the bottom," Det. Smith said as he showed photos to Maher.
"Now, I know that this photo obviously was taken a few months after the incident. Do you remember seeing any scuff marks along the side, the banister being pulled off -- the railing having an sort of marks on it, any blood anywhere around here?" Maher asked.
"Just a few days after the homicide we inspected the walls and the railing and the floors and the carpeting," Smith replied. "There was nothing. No blood on the carpet at all, the railing was fine, no -- damage, no problems at all."
Investigators also say one of the most disturbing red flags was a large bruise found on Karina's thigh.
"I think David stomped on her and kicked her. And that, right there, really made me and the other detectives think that we're dealing with an assault and not a fall," said Smith.
"Were you ever able to find a shoe that matched that in the house?" Maher asked.
"We didn't find a shoe that matched perfectly," Det. Smith replied.
Detectives may have strongly suspected David Ditto was lying, but they needed more solid evidence and they got it from San Diego County Medical Examiner Dr. Othon Mena, who says Karina Ditto did not accidently fall down the stairs. Instead, Dr. Mena says she was beaten and strangled.
"There were too many injuries to be explained by what we were told happened. I had to find what -- what it was the reason her heart stopped. And, in my opinion, it's because she was in -- asphyxiated, either by strangulation or by -- smothering while also being beaten," Dr. Mena explained.
Three days later, David Ditto was arrested.
Visibly shaken at his arraignment, Ditto went from a grieving husband to a man charged with his wife's murder.
Ditto's mother, Pat Doughty, couldn't believe it.
"When the judge -- stated that -- the medical examiner had said blunt force trauma and strangulation. We hadn't dreamed of that at all," she told "48 Hours".
Before March 12, 2011, there was no known history of abuse; no physical abuse that is.
"In Karina Ditto's life it was more about power and control. It wasn't until she started to break free from that relationship that he lost control," San Diego County prosecutor Claudine Ruiz said. "But he was not the type of abuser who would lose his temper and beat his wife. He was a cold, calculating man. And he made the decision to kill her."
"When you hear these words-- violent, controlling, jealous ..." Maher said to Doughty.
"Well, there was no violence," Doughty said. "There was no vi-- violence."
"These are not words that you associate with your son," said Maher.
"Absolutely not," said Doughty.
Even the one person who knew Karina best had her doubts.
Karina's mother believed David's story at first until she returned to La Paz and began to think about all those letters from Karina and all those bruises on her daughter's body. Eventually, and somewhat reluctantly, Silvia Benitez had a change of heart about her son-in-law.
"Why did he have the heart to cause a person so much harm, (pauses) he could've returned her to me, or divorced her... but not kill her," she said.
Those letters may have suggested motive, but detectives believe it is the physical evidence that proves murder.
"...she had blood in her hair that had -- coagulated. And then, the blood around her had already began to dry. It says to me that she had been down for a while. David had time to think about what he was gonna do, if he needed to straighten up the house before the paramedics came, because he knew he was gonna be under scrutiny," said Det. Smith.
And just like first responder Lisa Challender, detectives were equally troubled by inconsistencies at the scene.
"It's not consistent with a fall down stairs. The -- all the blood, everything is three, four feet away from the bottom of the staircase," said Det. Smith.
"Here's the most unexplainable element of that story to me. When you look at the pictures, at the bottom of the stairs, there is no blood," Maher pointed out to Ditto's defense attorney, Keith Rutman.
"That's wrong," he replied.
Keith Rutman argues it's absolutely plausible that Karina's head landed exactly where David Ditto says it did.
"You're saying this is where she landed. And there is a blood splotch there," said Maher.
"Correct. And it depends on how much blood you're looking at. Remember, if David is -- is kneeling next to her -- his pants had blood on them. That could've absorbed some of the blood," Rutman explained.
"No one saw her fall. So you can't say -- how she fell down the stairs."
"Every single one of the people who treated her and dealt with her -- every single one of them said these injuries are inconsistent with a fall," Maher noted.
"Right. And every day you hear of medical events that no one has ever heard of before," said Rutman.
"So you believe that every one of those people was wrong?"
"Every one of those people?"
"And you then believe this was just a freak accident?" Maher pressed on.
"Yes," said Rutman.
But no one other than David Ditto knows for sure what really happened that night.
"Did you strangle her?" Maher asked Ditto.
"No," he replied.
"He fooled people. People don't wanna believe that there is that side, that dark side," said prosecutor Claudine Ruiz.
"It's just -- it's not me," Ditto said. "It's not true."
As David Ditto's murder trial begins, prosecutor Claudine Ruiz wants the jury to focus in on the horrifying details of her version of this case.
"Karina Ditto was 38 years old. She would have been 39 today," Ruiz told the court in her opening statement. "She scratched at him with both hands. But he pinned her arms back and he restrained her with his body. Then he slammed the back of her head and her head started bleeding."
Ruiz marches witness after witness to the stand -- forensic experts and first responders like Ray McQueen.
"Based on that cardiac rhythm, that's a complete dead heart," McQueen testified.
Witnesses, like first responder Lisa Challender, make the case that Ditto's story of a fall down the stairs just didn't add up.
"And so for somebody to have fallen ... onto the tile surface, how come she was injured on both sides of her face and then the back of her head also," Challender testified.
But Ditto's lawyer, Keith Rutman, says the evidence points to an accident, refuting the police version of the scratches on David's face.
"The first element they say is it just does not make sense that somebody who's been given CPR would even be able to move their arms and reach up and scratch because that's why you're giving them CPR They're not breathing. They're not moving," Maher noted to Rutman.
"Wh -- right. But David testified she came to. So that point you would imagine that he would stop giving her CPR giving her the freedom to move about," he replied.
Rutman says investigators came to the wrong conclusions because they did a sloppy job.
"If you're conducting a criminal investigation into a murder of your wife by a husband while there's kids upstairs, you have to do it right!" he said.
In court, he tries to show the jury that procedures were not followed, the right questions were not asked.
Keith Rutman: Did you ever hear anyone ask him to explain how the blood got all over her body?
Lisa Challender | First responder: No, I never heard anybody asking that.
The biggest oversight, Rutman tells the jury, was that the county medical examiner, Dr. Othon Mena, did not have complete information when he examined Karina's neck.
"And his immediate explanation is, 'that's consistent with what we see in strangulation cases, so it must be strangulation,'" he said.
What Dr. Mena didn't know, according to Rutman, is that a resident doctor at the hospital accidently punctured an artery in Karina's neck while trying to give her blood to revive her.
"Never knew that arterial puncture had occurred, so was never able to discount that," said Rutman.
Rutman says it was that puncture that caused her neck to bruise ... not being strangled, as Dr. Mena testified.
The puncture was discovered by Rutman's star witness, renowned medical examiner Michael Baden.
"He reviewed the autopsy report and he reviewed all the medical records from the hospital and he was the one who first noticed that there was a potential contributing source of blood from the arterial puncture," Rutman explained to Maher.
"How does he believe Karina died?" Maher asked.
"Well, his testimony was -- to be technically correct about it -- was that her injuries were consistent with a fall down the stairs," said Rutman.
Dr. Mena says he was aware of the puncture.
"The defense believes that ... the mistake of the resident is the hemorrhage that you saw that you believed was strangulation," Maher noted to Dr. Mena.
"No. It cannot be because the two hemorrhages were separate ... the hemorrhage that was because of the resident placing a line was down here by the clavicle," Dr. Mena said. "The hemorrhages that I saw were over here by the thyroid gland or by the voice box."
Dr. Mena says Karina's injuries tell a story about what happened to her that night.
"What's the story you were able to piece together by the condition of her body?" Maher asked.
"Her body told me that she was beaten because she had way too many injuries to be explained by a fall down stairs," Dr. Mena replied.
And that is what the jury heard him say.
Then, Rutman took a big gamble by doing something that is rarely done in a murder trial these days. He put David Ditto on the stand so jurors could hear from David directly and judge for themselves if he was telling the truth.
"Karina was here at the base of the stairs. Her head was on the tile floor, her shoulders were flat on the tile floor," Ditto said, referencing a photo shown in court.
Then he addresses a key point to the prosecution's case: how Karina's head got to where the blood was on the floor.
"... so I was holding her and I lifted her head and shoulders and kinda just pulled her. And then just kinda took steps with my knees and pulled her several times until she was laying alongside the buffet," he continued.
Keith Rutman: Did you try to give CPR to Karina?
David Ditto: (Weeping) Yes I did.
Keith Rutman: Was she moving?
David Ditto: No, she wasn't.
Keith Rutman: Was she talking?
David Ditto: No, she wasn't. (Crying) ... I lifted her up and held her in my arms. Just her head and her shoulders. (sniff) I just said, "Honey, honey are you OK?" Trying to wake her up.
Keith Rutman: Were you able to wake her up?
David Ditto: (Overcome with emotion) No.
David Ditto also got emotional when he acknowledged there were problems in his marriage, but said both he and Karina were working hard to save it.
"And we talked a lot and cried a lot. But she said yes, and she wanted to try again," said Ditto.
Jurors had to weigh Ditto's testimony against that of Karina's mother, who told them of his controlling ways as described by her daughter.
"For example, water the plants at a certain time ... Food at a certain time ... The phone, she had set time to talk to us, to call us," Silvia Benitez testified.
In closing arguments, Rutman tells jurors that even if there were problems in the couple's marriage, that is not enough evidence that he killed her.
"She would tell her mother, 'Sometimes I feel like I wanna be single again.' Everybody feels that way! Everybody. At one point or another in your marriage, everybody feels that way," he said.
Rutman says the fact that David Ditto's story is so odd is precisely why it had to be true.
"You'd think if he planned all this he'd have a better story put together. The blood would be in the right places. The injuries would be consistent with what he saw. That's not what he said," he told the court.
He backs up his point that it was a freak accident with some mathematics.
"If it's a one-in-a-million chance that Karina Ditto fell down the stairs and hit her head in just the right way, if it's a one-in-a-million chance, that means it happened to 311 people last year. A thousand if it happens in China," Rutman continued.
But Claudine Ruiz isn't buying any of it. She wants the jurors to believe it was cold-blooded murder.
"This was no accident," Ruiz addressed the court. "And the bruises all over her body tell you that."
After four weeks of testimony, the case against David Ditto was now in the hands of the jury. His attorney, Keith Rutman was feeling optimistic.
"I was confident that we had presented the best case that -- existed and that they had left too many unanswered questions for 12 people to conclude that David just upped and murdered his wife in the middle of the night with his kids upstairs," Rutman told Maureen Maher.
Unlike Rutman, David's sister, Maggie Cascio, was not as optimistic.
"But after our attorney's closing argument, that's when I felt (pauses) worried," she explained. "Our closing argument just was not-- it didn't drive the points home."
It took only one day for the jury to reach a verdict and that made Ditto's mother, Pat Doughty, very nervous.
"I felt that -- because they came to -- a decision so quickly, they did not consider all of the evidence," she said.
David Ditto was found guilty of first-degree murder. The verdict stunned everyone who believed he was innocent.
"I never dreamed that they would find him guilty of first-degree murder. I mean, that was over the top," said Pat Doughty.
"I was shocked," said Rutman.
But no one was more shocked than the defendant.
"I really didn't think there was any way I would be convicted. I didn't think it would be possible to convince -- a jury of 12 people that I killed her when I knew that it wasn't true. And I knew that some of the evidence, you know, looks suspicious. And I saw some -- some problems," Ditto said, "but it didn't prove anything. I -- it didn't prove that I -- that I hurt Karina in any way."
"48 Hours" sat down with three of the jurors.
"Was there a particular piece of evidence or someone's testimony that came to the forefront right away?" Maher asked the jurors.
"Well, for me, it was - the -- the medical examiner's evidence," said juror Francine Foman-Maisel. She found that Karina's injuries told an undeniable story. "Just -- seeing the pictures of her ... just seeing that, because that was so objective and -- and convincing for me."
"Even though we had all the testimony about their relationship, everything, I was trying to go on the actual physical -- evidence that they brought forward. And it just didn't seem that they could possibly be from a fall down the stairs," said juror Christine Ellis.
Juror Patricia Woelk was not convinced by Ditto's story, either.
"I found his testimony disingenuous," she said. "And it seemed very disconnected from the context of the situation. And I -- I was troubled by that."
"It's sad to think that someone went through the kind of pain, at the end of their life, you know?" added Ellis.
Asked if she believes justice was served, prosecutor Claudine Ruiz told Maher, "I do."
Ruiz says the last chapter of Karina Ditto's life may have ended very differently if not for the first people who stood up for her.
"The paramedics were really the unsung heroes in this case because they arrived on the scene knowing nothing," she said. "And when they walked in they immediately knew something was wrong."
"Is it possible, then, he could have gotten away with murder and called it an accident?" Maher asked.
"He very well could have," Ruiz replied.
"I saw my role on this call as providing care for Karina Ditto. Every person that was involved in this had a part to it. I know that we were the first people to draw attention to it," said first responder Lisa Challender.
Nine months after Ditto was found guilty of first-degree murder, Judge Kenneth So sentenced him to 25 years to life.
"This is a tragic case," Judge So said. "It's tragic for the victim; it's tragic for the children."
Now 45, David Ditto will most likely spend the rest of his days in prison.
When the case against Ditto finally came to an end, Silvia Benitez was back home in La Paz, Mexico, where it all began for David and her daughter.
"I felt guilty, even today I still feel guilty, because had I told her to pack her things and leave him this wouldn't have happened," she told Maher.
As Benitez looks through a photo album full of memories, she hopes and prays she won't lose touch with the grandchildren she loves dearly, but hasn't seen since the trial.
"It's very difficult when I speak to them on the phone. I can't control myself when hearing their pretty voice," she continued. "They are not alone, they have a lot of family here and we love them."
The children are now living with David's sister and her family.
"You still have photos of David and Karina in your salon and all over your house. How do you feel about David Ditto today?" Maher asked Benitez.
"I only see him as a son who left, a son who made us feel good at one time, a son who behaved badly, but I have him in my heart, I don't hate him, I forgive him," she replied in tears.
Four months before Karina died, David Ditto took out a family life insurance policy. He never got to collect on it.
David Ditto insists he's innocent and is appealing his conviction. He will be eligible for parole in 2037. He will be 70 years old.
Need help or know someone who does? The National Domestic Violence Hotline provide resources and assistance 24 hours-a-day: : 1-800-799-SAFE | 1-800-799-7233