Thomas Toolan III is about to become a very famous man.
Opening arguments began this morning in a highly charged Nantucket murder trial that has all the elements of a Shakespearean drama for the tabloid set: a handsome Wall Street banker with alleged "wild child" tendencies and a beautiful young woman cut down in her prime in a cottage on an island paradise.
Toolan is accused of stabbing former lover Elizabeth Lochtefeld, 37, to death after she tried to break off their six-week relationship in October 2004.
"I met Tom Toolan a week before my sister died," Tom Lochtefeld told ABC News' Law & Justice Unit in an interview this week. "He seemed fairly normal. You have some apprehension. … He didn't put me at ease."
Like many brothers, Tom Lochtefeld said that he tried to get a sense of the boyfriend through his sister.
"Three weeks prior she was bubbling," he said. "All of a sudden she is not bubbling. … I'm convinced he was so arrogant he thought he could get away with it, but you've got to be held accountable."
It's been nearly three years since Elizabeth Lochtefeld's body, shredded with stab wounds, was discovered in a cottage she rented on the island. It was the first murder on the island in nearly a quarter century.
Toolan, now 46, grew up near Prospect Park in Brooklyn, N.Y. His two parents founded a Montessori school. Toolan reportedly graduated in 1991 from Columbia University in New York.
Toolan was arrested at an antiques show in 2001 at the Seventh Regiment Armory in Manhattan after New York City police said he tried to walk off with a 60-pound, $80,000 marble bust of a Roman aristocrat under his coat.
Toolan reportedly told a security guard who stopped him that he was "just pulling a prank." His attorney at the time told the New York Daily News that Toolan "had a lot to drink" that night. He eventually pleaded guilty to disorderly conduct. A short time later, he was asked to leave his job as a vice president at Citigroup.
Neither Toolan's parents nor his attorney, Kevin Reddington, returned repeated phone calls from ABC News for comment.
Elizabeth Lochtefeld grew up in Peekskill, N.Y., and spent summers during her childhood on Nantucket, where her father, John, is an artist and art gallery owner. She graduated from Notre Dame, traveled and taught English in Japan.
She moved to New York and began a consulting firm called Code NYC, which assisted architects and construction project managers trying to navigate the byzantine city building rules and regulations. The business was sold for about $1.5 million, her brother said.
After Toolan's arrest and the press surrounding the murder trial, his apparently dicey charm and reported mood swings became well-publicized.
After meeting Toolan on a plane, a Manhattan bartender named Becky Hammonds said she initially found him charming and well-spoken, according to The Associated Press. But on their first date, she said, he drank too much and became verbally abusive.
"At one point I was speaking with the bartender and [Toolan] said, 'You're being awfully lascivious with the bartender.' I was shocked," Hammonds told the AP. "I ended up running from him at the end of the night when I got out of the cab. "