A Playmate, a Ponzi scheme, jewels and murder

"48 Hours" investigates two unsolved Hollywood murders and the trail that leads through the Playboy Mansion and Wall Street

Two dead young men, an unsolved double homicide... linked to jewelry and a Playboy model. And at the beginning of the investigative trail is a self-indulgent Wall Street millionaire.

"Playmates, porn stars, the list was endless," Mark Yagalla explains "...I just became a sex-crazed maniac!"

Eleven years ago, Mark Yagalla was living most every man's fantasy - having sex with some of the most beautiful women in the world.

"...it was exhilarating! It was a drug. It was my high!" he says.

It was no small feat, especially for this 33-year-old man who stands slightly over 5 feet tall and who considered himself a nerd growing up in rural Pennsylvania.

"I was like No. 1 in my class. The kids resented me because of that," he tells Peter Van Sant.

Asked if he had any girlfriends or ever went on a date in high school, Yagalla replies, "No."

But he did take a keen interest in the stock market.

At age 13, Yagalla says, "I started with spending a lot of time in the library... ordered the Wall Street Journal, reading S&P reports, ordering annual reports, digging into stocks."

So what was the attraction?

"I had developed sort of this fairy tale from movies that if you get money, you become successful, you get the girl. And that was my drive," he says.

Like in the movie "Wall Street," Yagalla says "I wanted to be Gordon Gecko."

Yagalla says he made $100,000 trading stocks while in high school.

"My cousin backed me when I was 16 and I started trading S & P futures and tech stocks," he says.

Yagalla made millions more just a few years later with a hedge fund he'd set up.

"It was intoxicating," Yagalla says. "I was having a great time."

He was living his dream.

"As I was making money, it started with prostitutes," he says. By his own reckoning, Yagalla paid for thousands of them. "Sometimes three, four different girls a day."

Video: More from Mark Yagalla

Why so many girls?

"For me, it was a way to fill the void," Yagalla tells Van Sant. "Loneliness. I was compensating for it with sex."

In fact, Mark Yagalla says he became totally addicted to sex.

"I was just out of control... in a strip club, in a bathroom, whatever I had to do to get sex," he explains.

"It was a compulsion!" says Yagalla's lawyer, Brian Bieber. "Mark Yagalla's conduct makes what Tiger Woods did now look like a junior high school student going through puberty."

Yagalla's insatiable appetite led him to Michelle Braun, a striking woman, who's known as the sex queen of L.A.

"Mark had a huge appetite for women, he would have a girl every day of the week if he could ... I was - arguably - the most successful madam in the history of the world," she says with a laugh.

"She was the first person to really use the Internet to offer prostitutes," says Yagalla.

Braun ran a website called Nici's Girls.

"I only worked with famous women - Penthouse Pets, Playboy Playmates, porn stars, actresses, models," she explains.

Braun claims she offered these most desirable women to some of world's wealthiest men, most notably Tiger Woods.

"I never discussed sex with the girls or the clients," she says. "What I was being paid for was an introduction."

Video: Michelle Braun on the life of a madam

Try telling that to Mark Yagalla, one of Braun's earliest clients.

"And what would a girl like that cost you, typically?" Van Sant asks.

"Anywhere from $5,000 a night to $50,000 a night," replies Yagalla.

"So the geek in his high school who couldn't get a date was now buying, essentially, some of the most exotic women on planet Earth?"

"Any woman I wanted, yes."

"Were you also lavishing them with gifts?"

"Yes," Yagalla says.

He couldn't help himself. Yagalla bought many of his escorts expensive cars, furs, jewelry - even houses, costing him millions. But it was only when another woman introduced Mark to Sandy Bentley - who he began dating - that his spending really went into orbit.

"All the other girls were gold diggers, but Sandy was an educated gold digger," he says.

They were together for 13 months.

"Was Mark in love with Sandy?" Van Sant asks Michelle Braun.

"Madly in love," she replies.

"Was Sandy in love with him?"

"Madly in love with his money!"

Yagalla calls Sandy Bentley "the most expensive girl I've ever met in my life."

Asked how much he spent on her, Yagalla says, "About $6 to $7 million."

So how did he manage to pay for all of this?

"I was taking client money and there was no boundaries," he tells Van Sant.

"You were scamming your clients?"


Instead of investing their money in stocks, he used it to pay for his incredibly expensive sex-capades.

"I was running one big Ponzi scheme," Yagalla tells Van Sant.

"And in the end, people got hurt didn't they?"

"Very hurt."

FBI Special Agent Mike Degnan says Yagalla "just was the definition of greed... He just took whatever he could get and used it for his own personal use without any remorse for the people he was stealing it from."

But Mark Yagalla's world began to crumble.

"He owed a brokerage firm over $7 million and had bounced the check to them, and they were asking for their money," says Degnan.

"I dug such a deep hole - $40 or $50 million - that I could not get myself of," says Yagalla.

Police: Millions of dollars in hot jewelry leads to murder

When Sandy Bentley got wind of it all, Yagalla says she dumped him. "...pretty much did not want to have anything to do with me. She was moving on."

Moving on, he says, but keeping most of his extravagant gifts including a fortune in jewels.

Police believe it was that jewelry that got Michael Tardio and Chris Monson murdered.

"Michael Tardio didn't have street smarts," says Cox. He and other investigators believe Sandy Bentley hatched a plan with Michael Tardio to sell some of Yagalla's gifts under the table to raise fast cash.

"Oh, I'm a sucker," Yagalla says. "Sandy Bentley was a total manipulator."

Mark Yagalla is bitter and angry. But is he capable of murder?