BILLINGS — A 31-year-old Billings woman was sentenced to state custody Monday for attempting to poison her child with hair spray.

District Judge Russell Fagg said Tammy Lynn Grudzinski had betrayed her young daughter. Fagg rejected a request from Grudzinski’s defense attorneys for a six-year suspended sentence, instead imposing a sentence of eight years with the state Department of Corrections, with three years suspended.

Prosecutors had recommended a sentence of 10 years, with five years suspended.

Grudzinski previously pleaded no contest to a felony charge of attempted assault on a minor. Prosecutors agreed to dismiss a felony perjury charge in exchange for her no contest plea.

Grudzinski has a previous felony conviction and she was sentenced as a persistent felony offender, which carries a greater punishment.

She was taken into custody at the end of the hearing.

Grudzinski said in a statement read to the judge by a defense attorney that she agreed to the plea agreement “to get this over.”

Grudzinski wrote that her daughter, now 4 years old, asks her during their brief visits every two weeks when she can come home. The girl was taken into state custody after the attempted poisoning.

Fagg said Grudzinski deserved a sentence to state custody because the woman betrayed her daughter’s trust.

“You did this to your own daughter when she was completely vulnerable,” the judge said.

Deputy County Attorney Annie Peterson argued for a longer sentence, describing how Grudzinski had to twist a top off her daughter’s cup of juice to pour in the hair spray.

“We’re all asking ourselves in the courtroom today, what kind of mother would provide a child with a chemical solution in a sippy cup?” Peterson said.

Defense attorney Sandy Selvey said Grudzinksi has completed several treatment programs and is getting counseling. Lawyers on both sides agreed that had the child drunk all of the poisoned juice, the risk of the girl suffering a serious injury was slight.

The case began on Feb. 16, 2005, when staff at St. Vincent Healthcare called police to report they suspected a woman had put hair spray in her child’s drink cup. The 18-month-old girl was at the hospital for treatment of pneumonia symptoms.

Staff members said they first became concerned when a nurse went to refill the child’s cup and noticed a milky liquid and a chemical smell. The girl vomited a short time later, and the chemical smell was again noticed.

Prosecutors said when they charged Grudzinski that the case may involve a rare type of child abuse called Munchausen syndrome by proxy. The condition has been described as a form of child abuse in which a parent invents or induces illness in a child in order to get attention.

The perjury charge was filed in March 2006. Prosecutors said Grudzinski lied during a hearing when she testified that she had never before been informed of her rights when she was questioned about the poisoning incident. Prosecutors said Grudzinski had been informed of her rights in 2004 during questioning by a county detective about a theft.