An Indiana woman will spend decades in prison for killing a mother in 2015 and trying to pass off the woman's baby as her own.

Geraldine R. Jones, 39, pleaded guilty to voluntary manslaughter on Friday in the stabbing death of 23-year-old Samantha J. Fleming. She also pleaded guilty to criminal confinement for holding the 3-month-old child against her will. Jones will be sentenced on May 25 to 30 years in prison and 10 years of probation under a plea agreement, according to her attorney, Lisa DeLey.

"The state made the offer and Geraldine was satisfied with it," DeLey said. "She's ready to put this behind her. She's at peace."

Prosecutors said Jones drove to Fleming's home in Anderson on April 6, 2015, and posed as a state child services worker, dressed in business attire and with a binder of fake paperwork. Jones allegedly told Fleming she was there to drive her and her baby to a court hearing in Gary.

Fleming's 21-year-old boyfriend reported her missing on April 10, 2015.

Fleming's body was found in Jones' home in Gary on April 17, 2015. Fleming had been stabbed 10 times. The body was doused in bleach and placed in a plastic bin hidden in a closet.

Jones previously had told family and neighbors that she was pregnant with twins. Authorities found a furnished nursery in her home.

Although police believed Fleming was killed in Gary, authorities decided to prosecute Jones in Madison County because that's where the initial crime occurred.