Was Lina Kaufman strangled or is her death a medical mystery?

Produced by Lisa Freed
[This story first aired on Oct. 27, 2012. It was updated on June 22, 2013.]

AVENTURA, Fla. -- "I think about Lina every day. ... She was stunningly beautiful. She had class, elegance, style," said Adam Kaufman.

The death of 33-year-old Lina Kaufman in the early morning hours of Nov. 7, 2007, came without warning. The mother of two was living with her husband, Adam, in a wealthy suburb of Miami.

"This particular morning, it was about 5 o'clock. ... I remember waking up ... and seeing her not there. ... And I figured, OK, you know, she's with the baby. She's not in bed, she's with the baby," Adam told "48 Hours" correspondent Erin Moriarty.

"Right around 6 o'clock, I woke up again. She wasn't there. That's when I got a pit in my stomach. ... I remember calling. No response. I remember walking into the bathroom and seeing her there ... slumped over onto the magazine rack."

"I just remember being in a frantic mode to -- to save her," he said.

Adam Kaufman hysterically called 911 and unsuccessfully tried to revive Lina.

"When I got there ... Adam ... was at the top of the staircase ... Completely distraught. I've never seen him that way before in my whole entire life," said Adam's identical twin brother, Seth Kaufman.

"Eighteen months later was like a second death in the family," Seth continued. "A SWAT team came in with laser pointer rifles and threw Adam on the floor and arrested him."

Elaine Kaufman never imagined it would come to this -- that she and her close-knit family would be snubbed in their own community, an affluent suburb of Miami.

"I hear whispering when I go places," she explained. "Some people just ignore you. Some people don't wanna hear from you. "

"There are people in this town who think your son is a killer," Moriarty told her.

"Let them think what they want to think," Elaine Kaufman said. "And we're gonna show everybody that he's not."

Adam Kaufman, a successful real estate executive, husband and father of two, now found himself branded a murderer.

"You gotta be kidding me. How could this happen?" he told Moriarty.

But there are the photos taken after Lina's death that show marks on her neck. And in April 2009, a year-and-a-half after he says he found his wife unresponsive in their home, Adam Kaufman was charged with strangling her.

"There's a mistake," Adam told Moriarty. "What evidence is there? There's -- there's no evidence."

No one took the news harder than Adam's twin, Seth.

"It was devastation ... they might as well have locked me up," said Seth Kaufman.

"I can tell what he's thinking, what he's going through," he said. "We do feel each other's pain. ... That's how close we are."

Asked if his brother is scared, Seth replied, "Of course, he's scared."

The news of Adam's arrest and Lina's death shook everyone around them -- it simply didn't fit with the couple they knew.

"She was his soul mate," Seth said. "...they were just amazing together."

Did you ever see anything that concerned you about their marriage?" Moriarty asked Elaine Kaufman.

"Never. Never," she replied. "I saw them all the time. They were happy. They -- they loved each other."

Friends and family searched back in their minds. Did they miss something? Lina's mother, Frida Aizman, remembers a strange conversation she had with Lina just two months before her death.

"She said, 'Listen. If something happened to me, I want you to know that I trust my kids only to you,'" Aizman recalled. "I don't know why she ask me. I don't know what -- what her thought was in this moment."

But Aizman says there was no sense that anything was wrong on Nov. 6, 2007. She saw her only daughter at work at the family's upscale furniture business, never dreaming it would be the last time.

"I said, 'You look so beautiful, so classical.' And she said, 'Are you proud of me?' I said, 'Of course,'" Aizman told Moriarty.

"And how would you describe her mood?"

"She was very, very, very happy," Aizman replied.

At the time, Lina, Adam and their kids lived right around the corner from Adam's brother, Seth, and his bride-to-be, Raquel.

"Was Lina excited about the wedding?" Moriarty asked Adam.

"She was so looking forward to it," Adam said. "She was-- one of Raquel's bridesmaids. I was Seth's best man. She was her happiest."

That evening, Lina got a spray tan - her first - to prepare for the big day. On the way home, she visited a friend to show off her tan, have a glass of wine and a bite to eat. Adam was home, he says, taking care of 5-year-old Haley and 2-year-old Jake.

"So I remember her coming home around 11:00," Adam told Moriarty.

"Did you see her when she came home?"

"Yes. Yes, I was already in bed watching TV," he replied.

According to Adam, Lina undressed. "And you could definitely tell she was spray tanned. It just seemed a lot to me," he noted.

They went to bed and the next time Adam says he saw his wife was in the early morning hours of Nov. 7, 2007; she was in this bathroom, he says, slumped over the magazine rack.

"I remember going to -- over to her, seeing all this red stuff all over. Pink, almost frothy whatever it was," he explained. "And I remember grabbin' her from the back. And she felt cold.

"Lina, Lina, Lina, wake up," he continued.

At 6:10 a.m., Adam called 911:

"My wife is in the bathroom dying... She's on the floor dying.

There's blood. There's stuff coming out of her mouth, there's foam.

She looks pale. She looks sick. She has marks on her neck. I don't know what happened."

The 911 operator instructed him to give his wife CPR.

"Push down on her chest rapidly--30 times," Adam explained. "And then back to breathing into her mouth twice."

911 Dispatcher: I need you to do compressions. OK?

Adam Kaufman: ...21,22,23,24,25,26...

911 Dispatcher: Can you hear her breathing?

Adam Kaufman: No, she's cold. ...

911 Dispatcher: Did something happen? Did she fall?

Adam Kaufman: No. No... Oh my Go--Lina ...

911 Dispatcher: Calm down sir, help is on the way, OK?

"You told the operator there were marks on her neck. Where were those marks?" Moriarty asked Adam.

"Here, here," he replied, pointing at his neck. "There were maybe three or four of 'em that I could see."

It would take fire rescue teams 16 minutes to find the Kaufman home.

"They were frantic," Adam explained. "Putting something over her face, putting something in her mouth. ... Continually asking me questions about -- her health. ... I'm thinking, OK, what health problems does she have? Lina was always healthy to me."

Seth and Raquel raced over to help Adam and his children.

Seth Kaufman told Moriarty," We got there and they were working on her in the bedroom at that time. ... it was just an awful scene. It was just tough to --to -- to look at."

They couldn't save her. Lina Kaufman was pronounced dead at the hospital.

"I was numb. I -- I couldn't -- I couldn't think straight. I couldn't feel my body," Adam told Moriarty.

"What are you thinking had happened to Lina?"

"I had no idea," he said.

Adam had to break the news to Lina's mother.

"Adam was crying," Aizman recalled. "And then he said, 'She's gone.' ... 'Lina is gone.'"

"What did you think?" Moriarty asked.

"I don't know if I could think in this moment. I just -- the only one thought I have, that it's not true. That it's not true. She cannot leave me here without her. She cannot do this to me," she said.

Lina's friends, Melissa and Jennifer, were also in shock.

"I could not comprehend how a healthy 34-year-old woman just dies," said Melissa Fedowitz.

Something happened. And that was my question for months. What happened?" asked Jennifer Ben Sadon.

It was the question everyone was asking - including the Aventura police.

"There are officers who said you didn't act normal," Moriarty noted to Adam.

"How do you act? Is there a book on how you act when your wife just passes away," he asked. "How do you act?... How do you act?"

When Lina Kaufman was buried in November 2007, no one could explain why she died, making her loss even more painful.

"What did you think? What killed her?" Erin Moriarty asked Adam Kaufman.

"I didn't know. And it was very, very, very frustrating," he replied.

Frida Aizman raised her daughter and son in five countries before Lina settled in Florida.

Asked what she misses most about her daughter, Aizman told Moriarty, "I miss her love. I miss her smell. ...Her humor... Yes, I miss her a lot."

Lina was as brilliant as she was beautiful.

"She spoke Russian, English, Danish, Flemish, Hebrew. A little bit of Italian," said Adam.

Asked if she was sophisticated, Adam replied, "Very sophisticated ... and I was just in awe."

They met at a party and after dating three years Lina and Adam were married. Before long, Haley and Jake were born.

"I was just kind of patting myself on the back saying, 'Wow, you're a lucky guy,'" said Adam.

But in an instant everything changed. His wife of seven years suddenly died and for almost 18 months, no one seemed to know why. Adam says he repeatedly called the Dade County Medical Examiner's Office.

"And they all kept telling me, 'We're waiting on test results, we're waiting on test results,'" he explained. "And I kept calling and no return phone calls. No answers."

But in April 2009, the answer he got stunned everyone. After exhaustive testing, the chief medical examiner ruled that Lina died from mechanical asphyxiation. Adam was thrown in jail, accused of strangling his wife.

"I know my brother more than anyone in this world. And I know he's just not capable of anything like that. He just cannot do that," said an adamant Seth Kaufman.

Adam's family cared for Haley and Jake while he was behind bars. At a hearing two months later, his lawyers made headlines with a unique defense: they said the spray tan did it.

"A few hours before she passed away, she had a spray tan for the first time," Adam explained. "It is possible to have an allergic reaction from this. So that was -- that was our thought. That -- everything else was normal."

But prosecutor Kathleen Hoague scoffed at their theory. "It was a laughable defense, truly," she said.

Laughable or not, Adam Kaufman was released on a $500,000 bond. Tracked by an electronic ankle monitor, he went home to his family to prepare for trial.

It would take three years, but finally, in May 2012, Adam goes on trial for second-degree murder in downtown Miami.

As the prosecution case begins, first responders testify they found Adam's behavior suspicious.

"Mr. Kaufman, on the scene was sometimes very calm, just talking like us right now. ...And within a second he would be completely a grieving type, out of control ... It was almost like an act," first responder Michael Castro testified.

"Everyone acts differently under pressure," Moriarty noted to Hoague.

"True. But probably-- there's probably nobody that sees more of that than these people," she replied. "You know, they didn't think that it was real."

But more troubling, Adam's initial stories seemed inconsistent.

Paramedic Kimberly Burk says Adam told her that he found his wife slumped over the toilet.

"He said she was crouched over the toilet as if vomiting," Burk told the court.

But the doctor at the hospital says he heard a different version.

"She had some strange marks on her neck," Dr. John Stollard testified.

"And I asked him if he knew how those might have occurred. And at that point in time he stated that maybe the patient was laying on the magazine rack in the bathroom."

"Why would these people think that you had something to do with Lina's death?" Moriarty asked Adam.

"You know, I-- I-- I-- I-- I've pondered that for -- for years now," he said. "When someone that young and healthy dies, people want answers. And ... I can't give people answers they wanna hear."

Prosecutor Kathleen Hoague doesn't have all the answers either. Unlike most spousal murders, this one doesn't appear to have a motive.

"Is there any evidence that Adam Kaufman was having an affair?" Moriarty asked Hoague.

"No," the prosecutor replied.

"Is there any evidence Lina Kaufman was having an affair?"

"No."

"Is there any evidence that there were serious domestic problems in this relationship?"

"No."

"But isn't that gonna make it very difficult in front of a jury to believe that this couple who seem to love each other would just blow up one time and end up with-- with a homicide?" Moriarty continued.

"Well-- you know, the injury speaks for itself... I don't know that he necessarily meant to do it, but I know that he did it, because the injury to her neck here, there and the strap muscles," Hoague replied, pointing at her neck. "It was very deep, sustained pressure."

Hoague believes Adam and Lina got into a fight in the early morning hours of Nov. 7. Exactly what they fought about she isn't sure, but she says the proof is in the crime scene photos.

"You believe there was an argument that started in the kitchen?" Moriarty asked Hoague.

"I do, because her breakfast was half-done," she replied.

Hoague is certain the compulsively neat Lina Kaufman would not have left a bowl of cereal and half eaten banana on the counter. She believes the argument moved from the kitchen upstairs.

"She may well have just been going to the shower saying, you know, 'Screw you. I'm not gonna listen to you anymore. I don't want to talk about it," Hoague reasoned. "And you know, he just flew off the handle. 'Yes, you are,' grabs her and ... it's not that hard for someone as big and as strong as him to strangle someone."

"The prosecutor says that she believes that there was a fight that morning before. Did you fight with Lina?" Moriarty asked Adam.

"Absolutely not," he replied. "Lina and I argued just like every married couple. Did we argue that day? Absolutely not. ...Everything was perfect."

But some say things weren't quite so perfect. In the weeks before she died, Lina was threatening not to go to Seth and Raquel's upcoming wedding.

"There were some minor issues that I tried to stay out of," Adam explained. "There were some -- there was an issue with walking down the aisle."

Adam was Seth's best man. Raquel wanted him to walk down the aisle -- not with Lina - but with her maid of honor. That upset Lina, says her friend, Jennifer.

"When Lina found out that she wasn't walking with Adam, it-- it really set her off. It did," she said.

"You call it a minor issue. Some of her friends say it was a major issue," Moriarty pointed out to Adam.

"I can't say it did not bother Lina," he said. "Lina and I did talk about it. We did. And she was upset about it. Definitely was upset"

"Did you fight about that? Did that become a physical fight?"

"Not at all," Adam replied. "Not at all. No. Never. Never."

"She didn't do it to herself. You know, it has to be done by someone else. He's the only person that could have done it," said Hoague.

"I've never laid a hand ... on her in our entire relationship," Adam said. "Nothing happened ... look at the evidence."

To tell Adam Kaufman's side of the story, his family, luckily, had money to hire a "dream team" of defense attorneys -- two of Miami's toughest lawyers: Bill Matthewman, an ex-cop and Al Milian, who was a prosecutor for 12 years.

"There is absolutely no doubt in my mind," said Matthewman, "that Adam Kaufman is innocent of this charge. None, zero, zip."

Adam's mother, Elaine Kaufman, believes they're the perfect combination.

"Bill...never gets excited about things," she explained. "And Al is quite the opposite. He's a ball of fire."

To counter Kathleen Hoague and her prosecution team, the defense attorneys have suddenly changed their strategy. They're no longer blaming Lina's death on her spray tan because there's not enough evidence to support it. Now, they're attacking what they say was a botched investigation by the Aventura police.

"This case was assigned to a detective who had never -- conducted a homicide investigation," said Al Milian.

The lead investigator reported that Adam told emergency personnel conflicting stories about how he found his wife, but Adam's attorneys question those witness accounts.

"I've always been consistent with one story. One story that she was slumped over," Adam told Erin Moriarty.

"You didn't tell anyone that she was over the toilet, like she was throwing up?"

"Never. Never. Absolutely not. "

Adam agreed to show "48 Hours" how he found Lina.

"Where was she exactly?" Moriarty asked as she crouched down on the bathroom floor.

"We had a leather magazine holder/rack ... That was right here," he pointed out. "When I walked in she was on top of it. ...she was draped over and her head, if you turn your head to the right, like that, and her ... hair was in her face. "

"OK, but she wasn't on the toilet," Moriarty noted.

"No, it was almost like she was sitting on the toilet and then got up and this happened or was about to sit down on the toilet and this happened," said Adam.

But then how do Adam and his attorneys explain the suspicious injuries on Lina's neck that prosecutors say prove that she was strangled?

"When Lina Kaufman passed out, she fell onto a rack filled with very thick magazines," Bill Matthewman explained. "And those marks are consistent with her resting on top -- falling on top of those magazines in the magazine rack, and they're inconsistent with any type of fingernails or fingers of anything of that nature."

And those deep internal injuries inside Lina's neck? Al Milian blames them on the paramedics.

"They tried to intubate her. And-- and they made multiple efforts," he explained.

Witnesses admit that there were three failed attempts to insert a tube down Lina's windpipe to help her breathe:

Al Milian | Defense attorney: If a tube is jammed into a person's throat, it could actually cause damage around the throat area, isn't that correct?

Michael Castro | First responder: Yes, sir.

And Milian admits that Adam Kaufman might have caused some of the injuries himself in his desperate attempt to save Lina.

"I mean, do you think when you were giving her CPR you might have left some of these injuries?" Moriarty asked Adam.

"I can't tell you one way or another. I-- I'm working on my wife," he replied. "I wanna believe that I wasn't rough on her. ...Did I tilt her head back? I thought I did it gently. Is it possible that I didn't? Yeah, it's possible."

The other bruises and abrasions on Lina's arms and legs occurred, according to the defense, when Lina was being moved from room to room by firefighters -- not from a struggle with Adam.

"Nothing on her body indicates that she was involved in a struggle," Milian explained. "You would've expected to see that Adam would've had scratches on his face, on his arms -- on his hands, on his wrist, none of which existed ... That bathroom would have been full of marks ... And that tanning spray leaves trace evidence everywhere."

Crime scene technician Anna Howell admits in court she didn't find any marks on the wall:

Bill Matthewman | Defense attorney: Did you swab or test this side of the wall?

Anna Howell | Crime scene technician: No, sir, because there was nothing of evidentiary value on it.

But a defense expert enhanced photos and found what appeared to be traces of spray tan where Adam says Lina had contact with the bathroom wall.

And then there's the magazine rack that Lina was laying on. Howell took the rack as evidence, but says lead investigator Anthony Angulo told her to leave the magazines:

Anna Howell: By the direction of Detective Angulo, the magazines were not collected. ...there was no reason to collect the magazines because there was no evidentiary value on it. There was no blood, they were... they were not wet.

But Bill Matthewman contends there was some kind of fluid on top of the magazines, as seen in an enhanced photo, and it could have been crucial evidence.

Asked what happened to all that, Matthewman told Moriarty, "That's the $10,000 question. Where are those magazines? They're gone. They're not there."

"You can't test it."

"We can't test 'em," said Matthewman.

And then a development no one expected that raises even more questions about how this case was investigated:

Bill Matthewman: You're friends with Detective Angulo?

Anna Howell: I'm a co-worker of his, yes.

Bill Matthewman: But when you're off duty do you socialize with Detective Angulo?

Anna Howell: No sir.

But the defense knows it's not quite the truth, and the following day, in a stunning about-face, Anna Howell admits her real relationship with the lead detective:

Bill Matthewman: Did you have an affair with Detective Angulo?

Anna Howell: Yes, and my husband is well aware of it, sir, and I am happily married and I don't have any issues with that any longer.

"Did you have any idea that this crime scene technician ... had had a relationship -- with the lead detective?" Moriarty asked Hoague.

"No, none," the prosecutor replied.

"It wasn't about the affair," Milian explained. "It's about the lying and the motivation for covering up."

"Yeah, it was very, very bad for us," said Hoague.

But the biggest court battle is about to come.

"The experts say that it's not a homicide," said Matthewman. "The experts say that it's absolutely not a murder. And the experts say that it is a natural death."

"There are unexplained deaths that happen in this country every day ... people pass away from natural causes. ... and sometimes they can figure out what it is, sometimes they can't," said defense attorney Bill Matthewman.

And yet, a seemingly healthy young woman is dead with injuries and bruises on her neck and body.

The county's chief medical examiner, testifying for the prosecution, says there can be only one conclusion:

Dr. Bruce Hyma: Cause of death is mechanical asphyxia.

Joe Mansfield | Prosecutor: Mechanical asphyxia?

Dr. Bruce Hyma: Yes

Joe Mansfield: And what would be the manner of death?

Dr. Bruce Hyma: Homicide.

Homicide. Dr. Bruce Hyma tells the jury that Lina Kaufman was murdered when someone or something cut off her airways:

Joe Mansfield: And why would it be a homicide, Dr. Hyma?

Dr. Bruce Hyma: Given all of the totality of information and all of the injury...this mechanical asphyxiation could only occur at the hands of somebody else.

Dr. Hyma's opinion is backed by his former associate medical examiner who supervised the original autopsy:

Joe Mansfield: Did you know you had an asphyxia death?

Dr. Satish Chundru: Yes

Joe Mansfield: Did you know you had a homicide?

Dr. Satish Chundru: Yes.

But the defense has its own medical witnesses and they say something completely different:

Bill Matthewman: Was the death of Eleanora Kaufman a homicide?

Dr. John Marraccini: No!

Bill Matthewman: And why do you say that?

Dr. John Marraccini: The evidence does not point to that.

According to Dr. John Marraccini, a pathologist, Lina Kaufman died simply of undiagnosed heart failure. He says slides taken of her heart prove it.

"This area is where a normal heart muscle used to be and something happened. There was disease here. And disease changed the tissue from this, to this," he told the court, referencing an image of Lina's heart.

He tells the jury she had myocarditis, an inflammation of the heart.

"My opinion is she developed an irregular heartbeat. She collapsed," Dr. Marraccini testified.

That's also what Dr. Michael Baden, the former New York City chief medical examiner, concludes.

"Mrs. Kaufman died of a pre-existing natural acute and chronic myocarditis," Dr. Baden testified.

It's a shocking claim, especially since Lina Kaufman appeared to have no history of heart disease. But her husband now recalls unexplained fainting spells after they married.

"I remember standing at the bar at a club with her... and all of a sudden, you know, we're talking and she just collapses straight down. And luckily I was standing there, I caught her," Adam told Moriarty.

"...two to three seconds later she kind of came out of it. 'I'm all right. I'm all right.'"

There was a much more serious incident after Haley was born, Adam says. Lina had been home with the toddler when she suddenly collapsed.

"She had called me and said, 'I just fainted. I just passed out and I can't get off the floor' ... and I said, 'OK, I'm-- I'm rushing home," Adam explained. "I remember when I got home she was up. She was fine. Walking around like nothing had happened. "

"Didn't that concern you?" Moriarty asked.

"Of course. Of course," Adam replied.

But Adam admits Lina never sought treatment from a doctor.

"Why not push her to go see the doctor?" Moriarty asked.

"Yeah. ... She didn't want to go. She said she was perfectly fine," Adam said. "...and life was back to normal."

"Did you believe that she had a history of fainting spells --" Moriarty asked prosecutor Kathleen Hoague.

"No. No, her friends didn't -- you know, didn't corroborate that," she replied.

What's more, says Hoague, none of the doctors hired by the state believe the signs of inflammation seen in Lina's heart were serious enough to kill her:

Joe Mansfield: Any indication that she had trouble with her heart?

Dr. Bruce Hyma: No

Joe Mansfield: Any indication she had a preexisting medical condition -- signs of dizziness, shortness of breath, anything that would have caused you concern about what she had going into this?

Dr. Bruce Hyma: No

Joe Mansfield: Nothing?

Dr. Bruce Hyma: Nothing at all.

Joe Mansfield: Did you see any signs at all on Lina Kaufman's heart that suggests that she had congestive heart failure?

Dr. Chester Gwin: No.

Joe Mansfield: Dr. Mont, do you agree with the findings that Lina Kaufman had an active inflammation in her heart and evidence of a scar?

Dr. Erik Mont: I do not. ...I found nothing abnormal.

How could six reputable doctors - four testifying for the prosecution and two for the defense -- look at this same evidence, but reach such different conclusions? Was Lina Kaufman murdered or did she die of heart failure? Her husband's future hangs on that answer.

Dr. Gregory Davis isn't working for either the prosecution or the defense. He's the medical examiner for the state of Kentucky -- the expert "48 Hours" asked to look at all the evidence.

"Does a case like this scare you?" Moriarty asked.

"It does," Dr. Davis replied.

"As you sit here now, do you now believe you know what killed Lina Kaufman?

"I do."

"You have no question about it?"

"No question," he said. "She died of myocarditis that caused an acute cardiac dysrhythmia and caused her death."

It was Lina's heart that killed her. Not her husband, says Dr. Davis. He points to the evidence that convinces him.

"This pink thing is a heart cell. And these are inflammatory cells that are actually attacking and destroying that heart cell," he told Moriarty, referencing small dark cells on an image of Lina's heart. "That is true myocarditis, a true inflammation of the heart where the body's own immune system is actually attacking the heart."

And those injuries on Lina's neck? Sadly, says Dr. Davis, they may have been caused by Lina herself.

"If she were suffering a cardiac dysrhythmia, which causes -- can cause an air hunger in a patient whose heart is rapidly failing. She feels out of breath. It can be very common for a person to grab at their own neck in that kind of scenario," Dr. Davis explained. "I think she died a natural death."

Dr. Davis is just as sure of his diagnosis as is every medical expert who testified at trial -- proof that even in this age of high-tech crime scene investigations, what is written on a death certificate is not fact, but simply one doctor's opinion.

"I think these are honest, good physicians. But they are interpreting these finding differently and I know that be can scary because people's lives are on the line based upon these interpretations..." he said.

But even if all these doctors can't agree, 12 jurors are going to have to.

Two weeks into Adam Kaufman's trial, a surprising witness for the defense: Lina Kaufman's mother, Frida Aizman.

Bill Matthewman | Defense attorney: Do you love Adam?

Frida Aizman: Like my own son.

Bill Matthewman: Do you support him?

Frida Aizman: I'm here.

"I really believe that he is not guilty. He is not guil -- he did-- he has nothing to do with this," Aizman told "48 Hours."

Frida Aizman is Adam Kaufman's best hope.

"The fact that she was willing to come in there, and testify for Adam, and support Adam in front of that jury, was critical for us," said defense attorney Bill Matthewman.

Critical because, Matthewman says, she backs up Adam's claims that Lina had undiagnosed health problems that caused her death.

According to Aizman, Lina suffered fainting spells as a child.

"So what did you think, it was just normal that she would faint occasionally? Erin Moriarty asked Aizman.

"No. Of course, it's not normal," she replied. "...it was when she was little, we went to the doctors, of course. And they didn't find anything."

Now Aizman believes the reason her daughter asked her to take care of her children was because Lina knew she was ill. But prosecutors say there are no records Lina ever consulted a doctor about fainting spells:

Joe Mansfield | Prosecutor: Was Lina ever taken by ambulance to the hospital, in response to any one of these episodes she had?

Frida Aizman: No.

Joe Mansfield: So the fainting spells that you...observed in Lina were a long time ago, not close to her death?

Frida Aizman: Yes.

"If she thought Adam killed her daughter, why would she testify for him?" Moriarty asked prosecutor Kathleen Hoague.

"She has no idea what's going on between Adam and her daughter," Hoague replied. "She's never really seen the injuries to her daughter or-- you know, she only knows what the Kaufman family has told her."

In closing arguments, the defense emphasizes Frida's unwavering belief in her son-in-law.

"Adam Kaufman is not guilty," Bill Matthewman told the court. "Frida Aizman lost her daughter. Frida still supports Adam. Loves him like a son. Knows he's innocent."

But the prosecution questions her motive for testifying.

"Ladies and gentlemen, Mrs. Aizman has two beautiful grandchildren," Matthew Baldwin told the court in his rebuttal. "What do you think would happen if she didn't support him? Do you think for a second, she would be seeing her grandchildren? ...You think she's going to go against him?"

"Are you accusing me of lying?" Frida Aizman yells out in court.

Her outburst angers the judge, who orders Aizman to leave the courtroom.

"If there was a side of you that thought that Adam did have something to do with your daughter's death, would you have still defended him in court?" Moriarty asked Aizman.

"Of course not," she replied.

"Even to keep a father for--"

"Of course not," she said. "What-- what father he can be if he can do this to a mom to this kid? So what father he can be? Of course not."

On June 5, 2012, after a month-long trial, the case goes to the jury and the waiting begins. "It's a scary, scary, scary thing," said Adam.

His biggest fear: that his children, who have already lost their mother, will now lose him.

"Every morning I leave and I go to work and the kids go to school. And, you know, you hug the kids and you kiss the kids ... And you know you're going to see them," an emotional Adam Kaufman explained. "This morning was different. ...That hug and kiss was different."

After eight agonizing hours, the jury reaches a verdict.

"It was definitely that feeling of, 'OK, here it is. Here we go,' Adam recalled of the moments before learning his fate. "And-- and I stood up in between Al and Bill and put my head down and just thought of my kids."

"We the jury in Miami Dade County Florida, find as follows: The defendant is not guilty so say we all."

"All I heard was 'not guilty.' And I felt Bill grab me and Al grab me," Adam said. "I could hear the family. And crying and -- and I'm like, 'Is this it? Is-- is it over?'"

The man branded as a killer for more than three years is acquitted of his wife's murder.

"And it was -- amazing. It was unbelievable," Adam said of the verdict. "It was pretty overwhelming. It was -- it was overwhelming."

For prosecutors, it is a crushing defeat.

"Even though you're acquitted, aren't there still some people who wonder did you have anything to do with your wife's death?" Moriarty asked Adam.

"Of course there's people out there that are-- that are gonna sit and wonder," he replied. "The people that matter know the truth. And that's all I care about."

Adam Kaufman is now trying to get his life and his reputation back.

"Has it occurred to you that you might not be sitting here if it wasn't for Lina's mom coming forward and testifying for you?" Moriarty asked.

"Absolutely. Absolutely," Adam replied.

"She probably saved your life."

"Yeah. Yeah. I think so."

Saved by Lina's mom, Adam says, and Lina herself.

"I believe she's -- she was-- she was a big part of this entire process and she was-- she was watching over it," he said. "In the end Lina's heart saved my life."

Adam Kaufman is living with his two children and getting back into real estate.

Bill Matthewman is now a federal magistrate judge.