New York (CNN) -- Three men whose identities surfaced during New York's "Cannibal Cop" kidnap conspiracy investigation pleaded not guilty Thursday to their own conspiracy charges, federal prosecutors said. Michael Vanhise, Richard Meltz and Robert Christopher Asch entered not-guilty pleas to conspiracy to kidnap charges and remain in custody, according to Jerika Richardson, spokeswoman for the office of the U.S. attorney for the Southern District of New York. Vanhise was arrested in January after authorities uncovered e-mail conversations he had with New York police officer Gilberto Valle. In those online conversations, Vanhise agreed to pay Valle $5,000 to render a woman unconscious, stuff her into a suitcase and bring her to Vanhise's home in New Jersey, where she would be raped, according to authorities.
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An attorney for one defendant says, "This was nothing more than his fantasy life"
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Another defense attorney says motions will be filed on First Amendment grounds
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Feds say the 3 exchanged messages about kidnapping, torturing and killing women
According to the complaint against the three men, authorities allege Vanhise engaged in a series of e-mail and instant messages with @placeholder and Meltz beginning in 2011 during which they discussed and planned in great detail the kidnapping, torture and murder of women.