Ex-"Survivor" producer: "I didn't kill my wife"

Bruce Beresford-Redman, charged in the 2010 murder of wife Monica, speaks out on exclusive video captured by cell phone inside a Mexican prison

Their once vibrant marriage on the rocks and in danger of breaking apart, Bruce and Monica Beresford-Redman came to Cancun.

"We needed therapy a little bit. We sort of took a time out. It was her birthday. We took a family trip. We said let's go have a good time," Bruce Beresford-Redman told "48 Hours Mystery."

They'd check into the Moon Palace Hotel, a bit of heaven laced along a perfect beach... a peaceful place where a family might repair itself.

"You know...I'm not -- I wasn't the perfect husband. There are times since Monica's death sitting in prison, having nothing but time, that I thought that she probably deserved better," said Bruce.

He hoped Monica might forgive him for his affair with Joy Pierce.

"I saw him a few days before he left Mexico. He talked about the fact that he was trying to work something out with his wife -- but he was also prepared, if need be, to be divorced," said Jeff Wald.

"They had their squabbles. I mean they truly loved each other. They loved the children," said Bruce's mother, Juanita Beresford-Redman.

The children, Alec and Camila, got to come to Cancun too.

"They never took a holiday. They never took a weekend without them," said Juanita.

The family of four would sleep in the same room. Room 7816 was spacious and airy with an ocean view and even a Jacuzzi.

"We just said, 'Look, let's just go and have a good time,' and that was it. So while there were issues that preceded it, there weren't any issues going on at that time. We were just enjoying each other," said Bruce.

Monica and Bruce took Alec and Camila to a water park and a ride down an underground river.

"So at one point Bruce and the two kids clamored up the side of this slope onto a walkway," Bruce's father, David Beresford-Redman, said. "And in doing so he scratched his shins and ankles. I guess"

Those scratches, and others on Bruce's body, would later become one of the keys to the case and would raise suspicions about his entire story.

"Did either of you hear from her while she was in Mexico?" Troy Roberts asked Carla Burgos.

"Yeah, I talked to her on Sunday," she replied.

But Monica's sisters, Carla and Jeane, say the plan to repair the marriage was already falling apart. Monica found out that Bruce was still texting his girlfriend.

"She was devastated," Jeane said. "And I told her, 'Monica, don't worry. You know, come back here, just move on with your life.'"

April 5, 2010, was another beautiful day as the sun broke over Cancun.

"It was a morning that she disappeared. OK, it was a morning that I last saw her," said Bruce.

According to Bruce, Monica decided to take a trip into town.

"Monica's plan, and this was part of her birthday present, was to go shopping and spend the day just for herself, and go to some spas maybe," said Bruce.

Monica's sisters say that's just the first thing about Bruce's story that doesn't add up.

"How many times did I see my sister go to a spa? None," said Carla.

"Never?" asked Roberts.

"Never."

"Monica's not a spa person," said Jeane.

By 11 p.m., Monica hadn't come back. Bruce didn't call her, he says, because she left her cell phone in the hotel room.

"Her cell phone was so cracked and damaged, that you had to shout to make yourself heard. And she just didn't take it with her. So I couldn't call her," said Bruce.

"She didn't take her cell phone? She left the kids all day with him? She never does that, ever," said Jeane.

"She must have gone through cell phones like crazy. She would drop them in water. She dropped one in a sink. She would break them," said Juanita.

That night, Bruce says he was nervous and worried, watching his sleeping children and waiting for his wife.

"And of course had the sort of silly hope that I'll go back in the room and she'll be home. She'll be back, but she never was," he said.

The next morning there was still no sign of Monica.

"So I called the hotel, to the front desk and said, you know, 'I expected my wife back last night. She didn't come back. What do I do?'"

Then Bruce says he dialed his sister-in-law.

"When Bruce called you to say that Monica was missing, what went through your mind?" Roberts asked Monica's sisters.

"'Oh, my God. My sister missing. Monica?'" Jeane replied. "It doesn't make sense."

"'Monica went shopping.' I said, 'Oh really, why didn't she take the kids?'" said Carla.

But Monica would never come home to her children. And after a day, her deeply worried sister, Jeane, would head from Los Angeles to Cancun and begin her own search.

"I looked at him and I say, 'Bruce, where is my sister?'" said Jeane.

Two days later, the mystery of Monica's disappearance would come to a horrific end.

"What did the manager say to you?" Roberts asked Jeane.

"'They found your sister,'" she replied.

On what would have been her 42nd birthday, Monica Beresford-Redman's beaten, suffocated body was found, dumped like garbage, in a hotel sewer pit.

"How could someone put a person naked in the sewage. Very, very, very horrible," said Jeane.

"It's not something you're prepared to hear or to handle," Bruce said. "You know, you live your life, you meet a girl, you start a family, buy a house...all of a sudden everything you know and everything you love and you care about just sort of disappears."

After Monica's battered body was discovered, a roadmap began to take shape. And details emerged about her final hours in Cancun, leading police to focus on one suspect.

"They immediately question Bruce at length," said Jen Heger, a reporter for Radar Online, who has covered the case since the beginning.

"It is alleged that he did kill his wife and that his two children would be in the room," Heger explained. "It was one room with two beds."

Mexican police say screams came from that room the very night Monica went missing.

"Two teenagers that were staying in the hotel...heard screams coming from the hotel room that Monica and Bruce and the two children were staying in. These were female screams crying for help," said Heger.

Bruce says the screams came from his children, and that they were all simply playing a loud kids game.

"Remember it's one large room," David Beresford-Redman said. "Was there screaming? Clearly there was. Was there yelling? Clearly there was."

"Was there a woman crying out in distress?" Roberts asked.

"It couldn't have been," David replied.

But there'd be more. Hotel housekeepers say the day Monica died, there was a "Do Not Disturb" sign hung on the door of room 7816.

"The Mexican authorities believe that Bruce wouldn't allow the maids to clean the room that day because there was a dead body inside, and that dead body belonged to his wife, Monica," said Heger.

Mexican police would examine the electronic door lock and find that the night Monica disappeared someone had been in and out of the room multiple times. The implication: It was Bruce going in and out of the room looking for a place to dump his wife's lifeless body.

"I would get up. I would walk up and down [the] balcony outside our room, or I would walk around that area a little bit. But my kids were sleeping in the room, so I went back very quickly every time to check and see that they were OK," said Bruce.

The situation was chaotic. Still, what no one could quite understand was Bruce Beresford-Redman's final plans for Monica.

"I was at the police station and the mortuary guy was there in my room...and he asked me what I wanted to do with my sister's body," Jeane told Roberts. "And I told him, 'I'm going to bring her back to Los Angeles.' And he said, 'Oh, you are?' And I said, 'Yes, why?' And he said, 'Because Bruce just paid for the cremation."

"Why do you think Bruce moved to have Monica cremated?"

"Well, the only thing that I can think... at this point is to get rid of any evidence," said Jeane.

"Burn any evidence or whatever," added Carla.

Mexican police would continue their investigation. They had Bruce's passport, but it didn't really matter. Soon the star television producer was gone.