Gilberto Valle – dubbed the “cannibal cop” by US media – was arrested by the FBI last year after a tip-off by his wife, from whom he is now estranged.
The 28-year-old savage faces life in prison when he is sentenced in June.
Valle’s lawyers argued he had merely engaged in a role-playing fantasy he concocted while browsing fetish websites, and said they would appeal.
But prosecutor Hadassa Waxman told the US District Court in Manhattan that Valle had “left the world of fantasy and entered the world of reality” by contacting some of the women mentioned in his plans.
He was also convicted on a lesser charge of improperly accessing a law enforcement database to look up the women’s personal information.
Prosecutors told how he visited a street that was home to a woman he had agreed to kidnap for $5,000 for a honk from New Jersey, who is now awaiting trial.
Valle also used the internet to research the best rope for tying up people and to learn which chemicals render a person unconscious. Search terms found on his computer included “human flesh” and “white slavery”.
During the trial, Valle’s estranged wife, Kathleen Mangan, 27, testified against him.
She said she had found “thousands of emails” on her laptop, which he had been using, detailing his plans to like-minded fetishists.
“I was going to be tied up by my feet and my wrists and my throat slit, and they were going to watch the blood drain out of me,” she added.
Ms Mangan said that in the emails, Valle had discussed how two other women would be “raped in front of each other to heighten their fears”, and another would be roasted alive over a fire.
Both she and Valle wept when the court was shown a picture of him in his cop uniform, feeding their newborn daughter.
After Tuesday’s verdict, the US Attorney for the Southern District of New York, Preet Bharara, said: “Today, a unanimous jury found that Gilberto Valle’s detailed and specific plans to abduct women for the purpose of committing grotesque crimes were very real, and that he was guilty as charged.
“The internet is a forum for the free exchange of ideas, but it does not confer immunity for plotting crimes and taking steps to carry out those crimes.”
But Galle’s lawyer, Julia Gatto, said the conviction was flawed because the jury had focused on his “unusual and bizarre and frankly very ugly” thoughts, and not on the fact that no-one had been harmed.
“This is a dangerous prosecution, when we start opening up our minds and prosecuting what’s inside our brains and not in the real world,” she added. “We totally believe the government did not prove their case and the jury couldn’t get past the thoughts.”
The defence team said it would ask the judge to set aside the verdict.
Amid the investigation into Valle’s online correspondence, UK authorities arrested two men last month in Kent, England.
The pair, aged 57 and 30, from the Canterbury area, were released on bail while inquiries continued.