By Chris Hansen, Dateline Correspondent

It's our twelfth "To Catch A Predator" investigation and this time we're set up in a 6,000- square foot home in Bowling Green, Kentucky. It's a town of about 50,000 people an hour north of Nashville, Tennessee.

Each one of these investigations has its own rhythm and Kentucky is no different. Within hours I am struck by the fact that fewer men are showing up at our hidden camera house than in past investigations.

Looking back I think this at least partially because the Kentucky Attorney General's office and the Kentucky Bureau of Investigation, along with local law enforcement, have been actively pursuing online predators in the past year.

Before Dateline's investigation in Bowling Green, the Attorney General's office with the help of the online watchdog group Perverted Justice had conducted two previous sting operations without us, making 20 arrests.

One of them was a 59-year old criminal justice instructor at an Ohio college who used to be an elementary school teacher. He had been chatting online about having sex with a decoy posing as a13-year-old girl before showing up to meet her at the undercover house.

Even after this earlier high-profile case, though, we still saw men in our investigation eager to meet a young teen home alone for sex. As you will see, seven men show up over three and a half days and all seven are arrested after I talk to them and they leave the house.

You'll see in Kentucky that we employ the same online decoy, Casey, who we used in New Jersey. She is just as effective in this latest investigation as she was before talking to the men in person.

You'll see the grooming process in real time.

Also in Kentucky we see a range of men show up, from a factory worker to a man who says he's a police detective and carries a gun.

Watch the heart-pounding moments when, as he leaves our hidden camera house, he refuses to follow orders from the arresting officers.

'To Catch a Predator' Kentucky airs Friday, Dec. 28.

Click here for more about the series.

By Marianne O'Donnell, Dateline Producer

I saw a young man holding a sign with my name on it as I left the baggage claim area of Florence's main airport.

"Hello" I said, forgetting that English was not the lingua franca here.

"Buongiorno!" he smiled hesitatingly. "Ms. O'Donnell?"

"Oh, right, buongiorno," I corrected myself.

The driver said his name was Mauritzio, and for a moment I wondered whether the dispatcher of a car service or the editors of Vogue had sent him here. He had a perfect right angle for a nose -- what they call a classic Roman nose, I guess -- a defined jaw and dark hair gelled back. A lock of it had managed to escape the rest of the black slick; it curled seductively above his brow like an upside-down question mark. He wore a tailored blue pinstripe with a black leather coat and caramel colored loafers. He wasn't a driver. He was Adonis. As I seated myself in the back of his spacious Mercedes, he climbed behind the wheel, slipped on his black sunglasses and grinned into his rearview mirror.

"We go?" he asked.

"Uh, sure." I stammered. "I mean, good ... uh," since the breadth of my Italian started with 'bongiorno' and ended with 'arrivederci', with nothing in between, it was obvious I was going to need more than his driving skills.

"Bene?" he helped me.

"Right. Right. BEHH-nay," I parrotted. Saying it was a little like taking a rollercoaster ride. Up on the 'beh', down suddenly on the 'nay'. Italian was fun. "The Brufani Hotel in Perugia, please."

Ten hours earlier I had been sitting inside my senior producer's office in New York when I realized I was going to have to hotfoot it to the nearest airport and get myself to Italy. My assignment was to work the ground in a small city in the central part of the country. Perugia. I knew famous chocolates came from there, succulent Perugina Bacci's, but Dateline doesn't cover candy festivals. It does cover murders, though, and a particularly ghoulish one days earlier had left the town still shaken.

A young British woman, studying at the University of Perugia, had been stabbed in the neck and left to bleed -- slowly -- to death in the bedroom of a little cottage she had shared with three others. One of those was an American student named Amanda Knox. And if Italian police were right, she had something to do with her friend's murder. My job, among others, was to try to get an interview with Knox's mom, who had just arrived from Seattle to comfort her daughter, now in an Italian jail cell.

Days later, I waited in the bone-chilling wind that swept through the medieval piazza of stone and statues, along with my colleagues from Italian, British and American media. Word was the mother was due to walk through the piazza at any moment on her way to the office of her daughter's Italian lawyer. In one moment we were a rag-tag bunch milling around, in another we were a condensed cloud of bees, swarming toward a small, coated woman rushing along with her head down: the suspect's mother. The cameramen flicked on their lights. I took an elbow from one reporter in the ribs; a soundman behind me used my shoulder to steady his boom. Cameras, microphones, wires: we became one unholy body pressing in, cornering a terrified woman who looked back aghast at our communal brazenness.

"My daughter is innocent," she quickly said, in a trembling voice. "She's sure that as the investigation continues the truth will come out and she'll be proven innocent, ummm it's gone with one tragedy with the death of Meredith to know the tragedy that my daughter's living in. It's a terrible situation."

With that her lawyer led her forward by the elbow, into and through our shield. Of course we followed, wanting more, always more. She stilled looked terrified, but she offered nothing else.

In the weeks that followed we would all keep following the investigation for every new morsel of evidence: a bloody footprint found; a knife recovered; surveillance footage of suspects. As I stood with my press brethren in front of the courthouse off the piazza one afternoon, a stooped, white-haired woman caught my eye and shuffled over.

She wore a dazzling red coat and matching hat; her lipstick and makeup applied to perfection. She must have been in her 80s, but she was the epitome of Italian sophistication. She leaned on her polished wooden cane and began questioning me in her native tongue. I used my broken Spanish to try to understand. I got that she was distressed and a little embarrassed by the murder and worried what the rest of the world would think of her sleepy, medieval city on a hilltop, where such a crime, it seems, never happens.

But I clearly couldn't sustain a conversation with her.

In frustration she looked over at the cameras and reporters conversing around the door, waiting for the latest word from the prosescutor in the case. She sighed. I felt bad. "Non bene? Scusi."

I wasn't sure that my apology was properly worded or needed. At least she seemed to forgive my lousy Italian. "Grazie" she said softly, smiling. And she was off.

That night, after hours in the cold yielded nothing new in the case, I joined my cameramen, soundmen and fellow producer in a restaurant on the piazza.

Along with its chocolates, Perugia is known for its homemade pasta and wines. I was having a simple red from a local vintner. I took a sip, immediately relaxing as the wine swirled inside my mouth. In a long day, in what had been an exhausting week, it was a moment of bliss -- a little bit of 'bene' -- in a job that sometimes seemed to be anything but.

Click here for 'Deadly Exchange,' the full Dateline story about the case, including photos, video and a 'Who's who' gallery.
 

by Hoda Kotb, Dateline correspondent

You never know quite what to expect when you sit down to do an interview. So when Drew Peterson took a chair opposite me, I'll be honest:  I wasn't sure what was coming.

I knew his backstory well.  My producer Sue Simpson had provided me with information, news articles, police reports, autopsy reports.

His life did seem complicated -- when it came to women. This was a police officer with almost 30 years on the Bolingbrook Police Force.  He'd been married four times. His first three marriages ended in divorce; after he split from his third wife, she was found dead in her bathtub and his fourth wife, Stacy, was now missing.

I wondered if he was the unluckiest man on earth, with two of his four wives either missing or dead, or if there was more to the story. What would he tell me? 

Drew Peterson walked into the room. He had just finished an interview with Matt Lauer on the TODAY Show and was ready to sit in the chair opposite me.

He seemed calm. Collected.  I'd watched Matt's interview with him and he hadn't shown any emotion then although he gave lots of information.  I was expecting something similar.  Our camera crews and soundmen were all set up and ready to roll.

In the beginning, we talked about the media and how loud it was in front of his house in Bolingbrook, Illinois. He told me he was tired of  the generators from the TV live trucks going non-stop; he hoped this interview would put an end to the media chase.

He talked about Stacy: how they fell in love, the courtship, his proposals and their kids.

He also talked about the 30-year age gap, saying he had talked it over with Stacy,  adding that it was "exciting" to  have a young, beautiful woman interested in him.

Some of the things he said stood out including his description of how he pampered Stacy.   He got her, in his words, " a boob job. She wanted a tummy tuck, she got that. She wanted braces, lasik surgery, hair removal ... anything. ... we did all these repairs on her."

Then at one point in the interview he seemed overcome by emotion. He actually got up, left the interview area and said "I'm sorry. I need a minute."  He stood off-camera for a bit, composed himself and sat back down.

I wasn't clear what brought that emotional wave on, so I asked him.  He said, "Different things touch me off." And I when pressed him, he indicated that he'd been remembering Stacy's emotion at the time of her sister's death.  "Because it hit her very hard," he said.

He also told me that people didn't understand him: that he was a guy with a good sense of humor, a man who had tried to live an honorable life and worked hard to provide for his family, a man who was now being unfairly portrayed by the media.

Near the end of the interview, I asked him if he had anything to do with the disappearance of his fourth wife Stacy or the death of his third wife Kathy. He answered "no" to both questions.

Then Drew Peterson left the room and I was left with my original thought: you just never know what to expect when you sit down to do an interview.

Click here 'Deadly Suspicion,' the full Dateline NBC story about the case, including photos, a timeline, audio and documents.

By Dan Slepian, Dateline Producer
daniel.slepian@nbc.com

Imagine your loved one -- your brother, your son, your father -- is arrested, convicted and locked up for life for a murder he didn't commit. Now imagine he serves 15 years for this crime, and after all this time in prison, nearly everyone within the system agrees that he is, in fact, innocent. Then, when a Supreme Court Judge overturns his conviction and he finally gets out, the worst possible scenario happens: he is prosecuted on the same charges all over again. It couldn't happen, right? Wrong. It is happening right now, in

By Leonor Ayala, NBC News

From its dry arid deserts in the north to the frigid, icy landscapes of the south, Chile is one of the most geographically diverse countries in South America.  And according to environmental scientists it is also bearing the brunt of the damaging effects of global warming.

United Nations Secretary-General Ban Ki-moon visited Latin America  recently to see firsthand the effects of climate change. He  spent two days in southern Chile, touring Patagonia.

"The change is now progressing much faster than I had thought," said Ban. "It's alarming."

Ban Ki-moon's visit came just before the release of a much anticipated Intergovernmental Panel on Climate Change (IPCC) report on the impact of global warming.  The IPCC ,  which shared the Nobel peace prize with Al Gore, called for international treaties to limit the emission of greenhouse gases.

Click here for a slide show of Leonor Ayala's visit to Chile and Argentina.