Update: Rebekah Joy Wallin has pleaded guilty to second-degree murder in the disturbing March 2016 death of Bethannie Johnson, the three-year-old niece of her live-in girlfriend, Shanna Gossett. When asked by the judge in the case why she had decided to enter this plea, Wallin gave a simple answer. "Because I'm guilty," she said.

Back in January, as we noted in our previous coverage, on view below, Gossett offered her own guilty plea to the identical charge — second-degree murder — and in the beginning, she was the sole focus of inquiry in the case. Gossett's arrest affidavit, also shared here, contains a shocking litany of alleged actions. They include keeping Bethannie in a closet for weeks and reacting to a head injury suffered by the girl by concealing her body under a bed.

But weeks after her arrest, Gossett told authorities that Wallin was the driving force behind the abuse suffered by Bethannie. Her account included Wallin punching and beating the girl with a belt, culminating in the series of events that led to the child's death. Gossett said Wallin took Bethannie by the feet and threw her into a wall, causing severe injury and an alarming temperature spike. But Wallin allegedly didn't want to call 911 for fear that her actions would lead to her losing custody of her biological children.

No matter which of the women was most directly responsible for causing Bethannie's death, both face the same possible sentence. According to the Grand Junction Daily Sentinel, they can each receive between sixteen and 48 years in prison, with the judge given discretion to decide who gets what. They're scheduled to learn their fates on the same day, April 20.

Continue for our earlier report.

Update, 5:50 a.m. January 20: Shanna Gossett has pleaded guilty to second-degree murder in the death of her three-year-old niece, Bethannie Johnson, months after telling investigators that Rebekah Joy Wallin — her then-girlfriend, who's also been charged in the case — actually inflicted the injuries that killed the child.

Our previous coverage of this tragedy, originally published in April 2016, has been incorporated into this post.

In the beginning, Gossett, who served as Bethannie's guardian, was the only named suspect in the case, and the details contained in her arrest affidavit, which is on view below, were absolutely shocking. Gossett is quoted as confessing to having kept the child in a closet for two weeks and hiding her body under her bed rather than seeking help after she pushed the girl's head into a wall.

At 7:42 a.m. last March 17, the report states, Grand Junction Police Department officers and emergency personnel were called to a house on the 3000 block of North 14th Street on a report of a child who wasn't breathing.

Bethannie was found lying on the living room floor. She was warm to the touch but unresponsive. The child was pronounced dead shortly after 8 a.m.

Further examination showed that Bethannie had severe bruises on her head and abdomen — and when paramedics tried suctioning her airway, they found what's described as "older blood." Nonetheless, she hadn't been dead for long; personnel estimated that she'd passed away during the night or early in the morning.

Gossett told investigators that Bethannie was her sister's child. After the girl was taken away from her biological mother, however, Gossett was awarded guardianship.

Two weeks earlier, Gossett claimed to have met with a person whose name is blocked out in the report, asking that this individual look after Bethannie for a while, as she needed a break; she said the girl had "reactive detachment disorder issues" that caused her to throw herself around, thereby explaining the bruises.

She added that this person returned Bethannie at 10 p.m. the previous night, and while the girl had a minor bloody nose, she seemed otherwise fine. She put her down to sleep in her crib — but when she got up the following morning, Bethannie was in such dire condition that Gossett called for help.

It didn't take long for this story to fall apart; the person who supposedly had been watching after Bethannie for the previous two weeks was said to have been in Texas, not Colorado, during that period of time. And in a later interview, Gossett told an entirely different story.

Because she was having trouble controlling Bethannie, Gossett said, she strapped her into a high chair and put both the chair and the child into a closet. "She described concealing [Bethannie] there for two weeks," the affidavit states.

During that span, Gossett stressed that she'd continued to feed the girl and bathed her "periodically."

Then, on March 15, during one of the brief periods when Bethannie was freed from the closet, Gossett said the girl had thrown a temper tantrum. Gossett allegedly responded by pushing her down, "causing her to hit her head on a vacuum cleaner."

A moment later, Bethannie got up, but not for long. Gossett told police she pushed the girl's head into a wall, and the toddler stayed down this time — and stopped breathing.

CPR got her breathing going again, Gossett allowed, and the girl was moving her eyes. But instead of taking her to a hospital, Gossett said she hid the girl under her bed around 10 p.m. — the time she'd mentioned in her earlier account — before moving her to the crib.

Prosecutors charged Gossett with first-degree murder, child abuse resulting in death, second-degree kidnapping and false imprisonment. But in April, Gossett reportedly asked to speak with detectives about the case — and during that conversation, she implicated Wallin in the killing.

According to documents obtained by KJCT-TV, Gossett said that she and Wallin had been involved in a relationship that had turned sour. Wallin was controlling and wouldn't allow her to communicate with family and friends, Gossett allowed — and she was abusive to Bethannie.

An example offered by Gossett: Wallin allegedly tried to force the child to drink water by holding her head under the faucet of a sink. Then, in retaliation for the girl's negative reaction, Wallin was accused of striking her with a metal baking pan and forcing her to sit in a cold-water-filled bathtub for hours.

She added that Wallin previously punched Bethannie in the eye and made her eat spicy foods that caused her to choke — and maintained that the real reason the child had been kept in the closet was to hide her from visitors and Wallin's own children, seen in photos on her Facebook page, which is still online at this writing. She also mentioned a beating with a belt and an incident in which she swung Bethannie around by her legs, smashing her head into a glass cabinet.

In her account of violence prior to Bethannie's death, Gossett said Wallin made the girl run up and down a hallway — and when the child fell and hit her head against the wall, Wallin hit her with the vacuum cleaner, then threw her by the feet into a wall rather than allowing Gossett to offer help. Bethannie's temperature soon spiked, the document notes, but Wallin argued against contacting 911 for fear that her own children would be taken away from her. By the time emergency personnel was finally called, it was too late.

The following July, prosecutors formally charged Wallin with the same counts leveled against Gossett: first-degree murder, child abuse resulting in death, second-degree kidnapping and false imprisonment. Since then, both women have been involved in plea negotiations. Yesterday, as detailed by the Grand Junction Daily Sentinel, Gossett pleaded guilty to a reduced charge of second-degree murder, an offense that carries a possible sentence of between sixteen and 48 years in prison. Wallin, for her part, is expected to agree to an undisclosed plea deal next week.

Look below to see a larger version of Gossett's booking photo, followed by Wallin's mug shot and the Gossett arrest affidavit.