As the investigation into Tina Caronna's murder continued, friends, like Gary and Pat Hathaway, had grown increasingly suspicious of Tina's husband, Joe.
"I sat there everyday expecting at any moment, there's gonna be half a dozen squad cars come with the lights flashing and everything and they were gonna haul him off," said Gary. "To get him," added Pat.
But many questions remained, including why would Joe Caronna want his wife dead?
Searching for answers, some eyes turned to a woman the Caronna's knew from church, Becky Black.
"Becky Black was a friend of Tina and Joe's. And she started having an affair with Joe, started walking at the track in the gym and it started to grow into something more intimate and ended up lasting about eight-to-10 years," prosecutor Danielle McCollum explained.
"And did she cooperate?" Maureen Maher asked.
"Yes," McCollum replied.
"So right away, she copped to everything, the relationship?"
"Yes, said prosecutor Karen Cook.
Becky Black met Joe Caronna when she was in her mid-30s, feeling unappreciated in a troubled marriage.
"He was filling in the gaps of the stuff that I wasn't, you know, getting at home," Black told "48 Hours". "You know, opening the door and putting a rose on my door, my windshield, sending flowers to me at work."
"He paid her attention. He paid her compliments, like he did with Tina. And so that gave her, you know, a false sense of security with him and she was happy," said Cook.
Even after police questioned Black, she continued to see Joe.
"After the murder, I was kind of caught in between. I considered him my best friend," she continued. "I didn't want to betray my best friend."
But soon, her support turned to suspicion as Joe allegedly bullied Black. She had had enough.
"He was talking and he was getting meaner, more vocal, demanding that I do this and demanding that I do that," she explained.
Becky Black told her husband about the affair and her concerns about Joe, which she now also shared with police.
Seeing an opportunity, investigators convinced Black to keep the pretense of the relationship going -- and to meet Joe, in her car, in a parking lot ... wearing a wire.
"I was afraid for my family's safety and when they approached me to do that, I was more than willing," she said.
While Joe Caronna did repeatedly profess his love for Black in those recordings, he did not profess guilt:
Becky Black: Do you love me more than you did her?
Joe Caronna: Beyond a shadow of a doubt, I love you more than I've ever loved anybody.
Becky Black: All this time, I just kept thinking that maybe you - you know, you may have done that for me, thinking that was the only way that you could get me. And then I started thinking - at first I was scared - and then I thought, if you did, that made me feel...special, that made me feel like -"
Joe Caronna: Honey, I didn't do it. OK? And when I say I would do anything for you, I mean I wouldn't do something like that.
"He was convincing Becky that, you know -- he didn't do it. And the police don't suspect him. He told her multiple times, 'I'm off the list. You're off the list,'" said McCollum.
Actually, Joe Caronna was at the top of the list, but investigators doubted the affair was the motive for murder -- especially when they learned Tina had known for years Joe was cheating on her.
"There's a lot of people who think this was all about Becky Black," Maher commented to McCollum.
"I think Becky Black was just a side issue," she replied.
Investigators were still searching for a motive, when they learned about a home the Caronna's were planning to buy.
"Tina had been wanting a brand new house in Fayette County, a big house. And they had been discussing it since the beginning of 2008," said McCollum.
One week before the murder, after many delays, Tina believed the closing was finally going to happen.
"This house closing was a big deal to us, as far as realizing that he was really running out of time," McCollum continued.
Prosecutors believe that Caronna did not want Tina or the bank looking into his finances and that the closing was never going to happen. The reality was he did not even have an approved mortgage.
"When you fill out the application, they're gonna start checking your bank accounts. And ... Tina would have noticed it. And if Tina noticed it, she might ask questions," prosecutor Tom Henderson explained.
What Tina would have noticed, say prosecutors, was that Joe had built a financial house of cards: instead of investing all of his clients' money, his company, Caronna Investments, was scamming people - including Tina, their closest friends, and even his mistress, Becky Black.
"They didn't know anything. The friends and family had no idea," said McCollum.
"Because he was covering it up, using some fraudulent bank accounts," added Henderson.
Investigators scrutinized the Caronna's finances and found checks from clients and friends, like the Strunas.
"How much money did you lose with him?" Maher asked Matt Struna.
"Fifteen-thousand," he replied. "Caronna Investments is where we wrote the checks to. We traced the paper trail and found out that it went into his personal account."
And there was a $30,000 withdrawal from Tina's annuity, requested by Caronna, 10 days before Tina's murder and deposited into his own account 10 days after her death. Police say Caronna forged Tina's signature. Over a period of eight years, investigators say Joe Caronna conned his so-called clients out of more than $780,000.
"Joe Caronna was in trouble because his con was about to be exposed ... because Tina ... wasn't stupid," Henderson explained. "If she were to find out that he's stealing from their friends and relatives and hiding it from her and defrauding her, that would have been the end of it. And he'd have been back working at the Shoe Carnival"
"Or he would have been in jail," said McCollum.
Finally, police had a motive. They believed Caronna was so afraid of Tina learning about and exposing his scam, he killed her.
With this new knowledge of shady financial dealings, authorities went to search the Caronna home for evidence, but Joe was nowhere to be found.
"As the pendulum starts to swing toward Joe Caronna, that's when he decides he's gonna bolt and, of course, flight is a real big indicator of guilt," said Cook.
Nearly five months had passed since Tina's murder, and now, with Joe missing, a warrant was issued for his arrest.
"I thought he ran to Canada of Mexico or something," said Gary Hathaway.
"Mexico, I thought. He liked warm places," said Pat Hathaway.
But after a 17-day search, Joe was found much closer to home. A tip to a Crime Stoppers line led police just 77 miles away to a hotel in Jackson, Tenn.
"He has said that he was not on the run," Maher noted. "Couldn't he just have been visiting someone?"
"Sure," McCollum replied, "But then when police knock on your door at the Howard Johnson and you scream out, 'I've got a gun.'"
Joe Caronna was armed. But so were the cops who knocked on his hotel room door. After just 15 minutes of negotiating, Caronna surrendered.
With a mountain of circumstantial evidence, prosecutors charge Caronna with first-degree murder. They feel they now have their man - and his motive -- but with no physical evidence, do they have a case?
"We didn't have the best shot in the world, but we were gonna take the shot we had, because that's what we are supposed to do," said Henderson.