Inside Bizarre Case of an Indiana Surgeon Accused of Plotting Ex-Wife’s Murder

— -- After a whirlwind romance, Joannah fell hard for Dr. Gregory Konrath, a prominent orthopedic surgeon she met on an online dating site. She thought they would be married and even bought a wedding dress.

“He was looking for the same things, looking for a serious relationship,” Joannah, who asked that her last name not be used, said in an exclusive interview with ABC News' “20/20.” “We seemed to have similar things in common.”

But while on vacation in Puerto Rico, Joannah secretly recorded a shocking conversation with Konrath, where he appeared to be describing a plan to kill his ex-wife Ana as their children slept in their rooms.

After Joannah went to police with the recording, detectives searched for evidence to prove that Konrath was indeed plotting to kill his ex-wife.

Today, Konrath is behind bars serving a nearly 10-year sentence. But it’s not for attempted murder. Watch ABC News' "20/20" HERE to find out why.

Who Is Dr. Gregory Konrath?

Dr. Gregory Konrath lived in Peru, Indiana, and earned as much as $1.7 million a year specializing in orthopedic trauma.

An avid mountain climber, Konrath is one of less than 300 people who have climbed to the highest point on all seven continents. In 2010, he became a published author with his international spy thriller, “The Children Are Finally Safe.”

Outside of the operating room, Konrath was generous with his time and his money. According to Stephen Foht, the owner of Peru’s bar Boondocks, Konrath once bought several shots for the entire bar.

“It was everybody,” Foht told “20/20.” “I believe he had probably spent about $3,000 in our restaurant bar that night.”

And after the 2010 earthquake in Haiti, Konrath volunteered to help provide medical treatment to local residents.

Konrath and his ex-wife Ana Konrath had three children together but the couple divorced before his 50th birthday. Ana Konrath declined to comment for this report.

Konrath turned to the online dating site OurTime.com, where he met Joannah.

Konrath Meets His Girlfriend Joannah

Joannah, a nurse, mother and divorcee, said she was impressed with Konrath from the start.

“He was always a gentleman. He always came down to pick me up. Lots of times he brought flowers. He was a romantic, a gentleman, opened the door,” Joannah told “20/20.”

After four months of dating, the two moved in together. Joannah said he often spent a lot of money on her and bought her expensive things.

“I met his mom. I met his children. We went to his children’s games. We sat next to his ex-wife,” Joannah said. “[His ex-wife Ana] was nice. Greg and her got along fine. We did that regularly.”

Joannah had hoped she and Konrath would get married. She said they had looked at rings and she had purchased a wedding dress.

Joannah Records a Terrifying Conversation With Konrath

On Fourth of July weekend last summer, Joannah and Konrath took a trip to Puerto Rico. Joannah said they had been dating for 10 months at this point.

After a day at the beach, the two had drinks at their hotel, and that’s when Joannah said the conversation turned sinister.

Joannah decided to secretly record the conversation for 23 minutes on her cell phone as Konrath appeared to explain a plan to sneak into his ex-wife’s house at night and shoot her while their children were asleep in their rooms.

“She has a million dollar life insurance policy. I’m the beneficiary,” Konrath is heard saying on the recording.

On the recording, Konrath also told Joannah he would use hollow point bullets, make it look like a suicide and laid out the challenges and risks.

“He wasn’t just blowing off steam. He talked about, you know, buying a gun and hiding it and where he was going to do it and how he was going to do it and how her body was going to fall, and he’d done research,” said Joannah.

Joannah later told Konrath she was getting another room in the hotel, but she was actually planning her return to Indiana. Before leaving, she waited for Konrath’s paycheck to clear and withdrew thousands of dollars from their joint checking account.

Joannah Shows Police Her Recording of Konrath

Back in Indiana, Joannah ignored Konrath’s attempts to contact her. From Puerto Rico, Konrath asked police in Indiana to check on her saying he was concerned for her safety.

When police arrived at her door, Joannah played them the recording she took of Konrath’s alleged plot to murder his ex-wife.

On July 5, 2014, police interviewed Konrath about the recording. Miami County, Indiana Sheriff's Office Det. Sgt. Mike Rogers also searched the rental home Konrath shared with Joannah.

“All the evidence was there,” Rogers told “20/20.”

Inside the home’s garage, police found a gun and rubber gloves, pictured above.

Konrath Charged With Attempted Murder

At the home, police also found a set of scrubs and a set of sweats (pictured above) that Konrath said on the recording he was going to wear for the murder.

“I was convinced at that point -- and I still am – that he intended to kill his ex-wife, so we charged him with attempted murder,” Prosecutor Bruce Embrey told “20/20.”

But Embrey later dropped the charges, because the law in Indiana says the accused must make a substantial step towards committing a murder in order to be charged with attempted murder.

“You had to be in the vicinity with the means to commit the murder,” Embrey said. He explained even if a jury found Konrath guilty the judge would have to throw the case out. “We couldn’t get the case past the judge.”

But it wasn’t attempted murder that would lead Konrath to prison.

Konrath Denies Alleged Plot to Kill Ex-Wife

Konrath says he never intended to kill his ex-wife and called his alleged murder plot recorded by Joannah a “fantasy.”

“It’s vacation, so I was drinking a fair amount. Then I just told her about this kind of, I guess, dark fantasy that I had about killing Ana,” Konrath told ABC News' "20/20" in a jailhouse interview. “It’s an ugly recording. I am embarrassed that I did it.”

"I have never seriously hurt anybody," he continued. "And I don’t have any desire to kill somebody in real life. So if you talk to me about would I want to kill Ana when I am sober, I would say, 'No, I don't want to.' And not only that, but I am not gonna take a chance on my life being wasted by an attempt."