Authorities say the man, Michael Vanhise, agreed to pay Officer Gilberto Valle $5,000 to kidnap the woman in New York and deliver her bound to Vanhise's home in New Jersey, where she would be raped and killed.
Attorney Julia Gatto spoke Friday after Vanhise, 22, of Trenton, appeared briefly in U.S. District Court in Manhattan, where he was ordered held pending a bail hearing Monday on a conspiracy to commit kidnapping charge.
"Mr. Vanhise is being used as a pawn by the government to bolster a very weak case," Gatto said outside court. She represents Valle, a 28-year-old New York City police officer from Queens. He is scheduled to go to trial later this month after being charged in October with one count of kidnapping conspiracy and one count of accessing a computer without authorization.
Gatto said Vanhise "would have exonerated our client" with testimony about his own participation in a world of Internet sexual fantasies where people could speak of unspeakable acts they would never commit. She said the arrest Friday appeared to be a tactical move by authorities to prevent testimony by Vanhise or others about Internet fantasies.
"He definitely could have been a defense witness, yes. We believe he would certainly support the defense," Gatto said.
The lawyer said the government appeared to be pressuring potential defense witnesses not to take the witness stand by saying in court documents filed against Vanhise that there were other co-conspirators who had not been charged in the case.
Authorities say Vanhise also participated in planning the kidnapping of a girl.
Vanhise's lawyer, Alice Fontier, said her client, an auto mechanic who seemed to wipe tears from his eyes during his court hearing, was "very upset," especially because he wanted to be home after his wife gave birth to a daughter last month, one of several young children the couple has.
She said he had been in contact with the FBI since late October and there had "certainly been ongoing meetings."
"He has not stopped cooperating," she said, though she added: "Obviously, the relationship has changed since he was arrested."
Besides being accused of agreeing to pay Valle for the abduction last year when Valle was an active police officer, Vanhise also admitted emailing others about kidnapping, raping and killing women and children, the FBI said in court papers.
The FBI quoted Valle in court papers as saying in an email to Vanhise that it would be hard to restrain himself when he knocks the woman out, "but I am aspiring to be a professional kidnapper and that's business."
It quoted him as also saying he would tie her hands and bare feet and gag her. "Then she will be stuffed into a large piece of luggage and wheeled out to my van," it said he told Vanhise.
"Just make sure she doesn't die before I get her," Vanhise was quoted in court papers as telling Valle in response.
"No need to worry. She will be alive. It's a short drive to you," the officer was quoted as responding.
Valle was charged last year with using a law-enforcement database as he allegedly made plans to kidnap, rape, kill and eat women. Gatto said at that time that he was engaging in sexual fantasies and intended no violence.
In court papers filed Monday, defense lawyers wrote that Valle was accused from January 2012 to Oct. 24 of conspiring with others he met on a website devoted to the exploration of deviant sexual fantasies.
"Mr. Valle and the individuals with whom he communicated discussed, among other things, their violent sexual fantasies of abducting, raping, murdering and cannibalizing women," they wrote. They said Valle sometimes distributed the photographs of women he knew through his social network "to enhance the fantasy," though he never intended for any acts to be committed in the "real world."
U.S. Attorney Preet Bharara said Vanhise engaged in conduct "that reads like a script for a bad horror film."
He said the arrest was the second "in this bone-chilling case, but we are not finished."
George Venizelos, head of the New York FBI office, said the charges "convey the depravity of the offense."
The court papers said Vanhise also emailed photographs of a girl whom Vanhise knew well. They said this occurred after other unidentified co-conspirators expressed interest in kidnapping the child.
If convicted, Vanhise could face life in prison.
Associated Press Writer Colleen Long contributed to this report.