Federal prosecutors have combined two cases that both reportedly have ties to the investigation of so-called "Cannibal Cop" Gilberto Valle.
Prosecutors say the convicted New York City police officer agreed to kidnap a woman for $5,000 and bring her to a man from New Jersey named Michael Van Hise, who was arrested in January.
Van Hise is facing conspiracy charges.
In the other case, two men are accused of conspiring to kidnap, torture and kill women and children.
Christopher Asch, 60, is a former librarian at Stuyvesant High School.
Richard Meltz, 65, is a police official with a Massachusetts veterans hospital.
They were arrested earlier this month.
A source said their plot was revealed through the Valle investigation, but the connection is still unclear.
All three of the accused men will enter pleas at their next court appearance on Thursday.
Valle was convicted of kidnapping and conspiracy charges.