An Oklahoma City woman who prosecutors say dressed like a witch while severely abusing her 7-year-old granddaughter was sentenced last week to life in prison, PEOPLE confirms.

It was two months ago that Geneva Robinson, 51, and her 33-year-old boyfriend and co-defendant, Joshua Granger, pleaded guilty to child abuse and neglect charges.

On Thursday, Robinson learned she’ll spend the rest of her life behind bars when she received three life sentences; Granger received a 30-year sentence for helping Robinson commit the abuse.

The defendants initially faced a combined 29 counts of felony child abuse and neglect.

Robinson assaulted her granddaughter for more than a year, prosecutors said, including burning the girl with cigarettes, smacking her in the face and beating her with a rolling pin.

She painted her skin green and dressed in black whenever assuming the persona of the abusive “Nelda the Witch,” according to court documents obtained by PEOPLE.

Robinson also removed the girl from the local school system and deprived her of food. Court records further confirm Robinson often forced her granddaughter to sleep outside with her dogs.

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As she was sentenced, prosecutors also released cellphone video showing some of her abuse.

In the footage, which PEOPLE declined to publish, Robinson appears dressed as “Nelda” and grabs the girl by the throat before dragging her across the floor.

She tells the child she’s going to eat her, according to the video.

Abusive grandmother Geneva Robinson dressed as

A History of Violence

Detectives began investigating Robinson in 2014, after receiving a call from workers at Griffin Memorial Hospital in Norman, Oklahoma, where she had tried to have her granddaughter committed - saying she couldn’t control the girl.

The victim told investigators her grandmother regularly whipped her, beat her and pinched her skin with pliers, court documents state. She also said she went days without eating.

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The girl told detectives her grandmother would wear a green mask and bring her into the garage, where she was restrained and forced to sleep on a pair of pants, according to the documents. Robinson also used a pink dog leash to tie her up and suspend her from the ceiling.

Inside Robinson’s home, police recovered the leash as well as a horse whip.

Court records indicate Robinson allegedly utilized her “Nelda” character on others, including the girl’s father when he was a child.

The victim, who is now 9, addressed Robinson in a letter that was read in court on Thursday, a court official confirms.

“I love you,” the girl wrote, the official says. “I forgive you. You’re the best grandmother I ever had.”

It was not immediately clear in whose custody the child is now.

Lawyers for both defendants were unavailable for comment Monday afternoon.

This article was originally published on PEOPLE.com