WALKER, Mich. - A woman who spent 30 years in prison for her role in the deaths of residents at a Michigan nursing home was released on parole Thursday, officials said.

Relatives of victims had sued to keep Catherine Wood locked up, but a Kent County judge in October s aid he wouldn’t block the parole board’s decision.

Five people were suffocated at the Alpine Manor Nursing Home in Walker, near Grand Rapids, in the late 1980s. Wood pleaded guilty to second-degree murder and conspiracy and was sentenced to a maximum prison term of 40 years.

Wood, 57, has been released from a federal prison in Tallahassee, Florida, and will live in South Carolina, said Chris Gautz, a spokesman at the Michigan Corrections Department.

Investigators said Wood’s co-operation was crucial in prosecuting her companion, Gwendolyn Graham. Wood said she was the lookout for Graham, who is serving a life sentence in the suffocation deaths.

Wood was placed in a federal prison to separate her from Graham, now 56. Michigan only has one prison for women.