BEDFORD HILLS, N.Y. — Pamela Smart, a New Hampshire school employee who was sentenced to life after her teenage lover killed her husband, claims in a lawsuit that she was wrongly put in solitary confinement for 90 days.

Smart was a media coordinator at Hampton’s Winnacunnet High School when she seduced a 16-year-old boy in 1990. He claimed she threatened to break up with him if he didn’t kill her husband; she has denied planning the murder.

In a lawsuit amended this week, Smart says she was wrongly punished after a plastic utensil used to slice cheesecake was found in her cell.

A spokeswoman for the New York Attorney General’s Office, which is representing prison officials, had no immediate comment.

Smart’s case inspired the novel and movie “To Die For.”