"I would never intentionally hurt anybody," he said, his voice often cracking as he spoke. He also apologized to the family of the victim. "Now I've lost everything, my business, my family, my freedom."
But Castel handed down what he described as a "stiff" prison sentence, fined him $250,000 and ordered three years of supervised release.
"Thomas Hoey sees himself as a good guy," the judge said. "In truth Thomas Hoey Jr. is a self-obsessed, self-pitying, selfish man who is a danger to the community."
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Hoey's attorney, Ronald Fischetti, said he would appeal.
The sentence came days after federal prosecutors unveiled a new indictment charging Hoey with embezzling $800,000 from his company's retirement plan to pay for expenses.
In the case at hand on Thursday, Hoey pleaded guilty in August to conspiracy to distribute cocaine and suborn perjury, and obstruction of justice.
In 2009, Hoey met with two women at Manhattan's Kitano Hotel and offered them cocaine before having sex with both of them, prosecutors said.
After one of the women, Kimberly Calo, overdosed, Hoey refused to let the other woman, Nicole Zobkiw, his girlfriend at the time, call an ambulance. Instead, he called a friend who was a physician's assistant.
When Calo eventually received medical attention, she was declared dead, prosecutors said.
Hoey admitted in August that he had attempted to get Zobkiw to give false testimony to a grand jury investigating Calo's death. Zobkiw later died of a suspected cocaine overdose.
A jury earlier convicted Hoey of third-degree assault and tampering with evidence in the 2012 beating of Alison Bretherick on Manhattan's Upper East side. Bretherick sat in the public gallery at Hoey's sentencing.