Two weeks after she walked into an Arkansas emergency room cradling a dead toddler, a 20-year-old Arkansas woman is facing criminal charges stemming from the death of her 18-month-old daughter — while her boyfriend has been charged with murder.

A statement from the Fort Smith Police Department obtained by PEOPLE confirms Sierra Johnson has been charged with permitting abuse to a minor, a felony.

The statement alleges Johnson and her live-in boyfriend, 25-year-old Tyree Williams, walked into Sparks Hospital in Fort Smith on Jan. 30, carrying the “obviously deceased” girl.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Two days later, Williams was charged with the girl’s murder. He has pleaded not guilty.

According to the police statement, Williams allegedly confessed to punching the girl, Kylah Woodard, in the stomach.

Physicians tried resuscitating Kylah “but were unfortunately unsuccessful,” the statement reads.

Williams is being held without bond. PEOPLE was unable to determine if he has hired an attorney who could comment on his behalf.

Kylah’s exact cause of death has not been determined. But police allege that the toddler’s body was severely bruised.

• For more compelling true crime coverage, follow our Crime magazine on Flipboard.

It was unclear Wednesday if Johnson had entered a plea to the charge against her.

She does not have an attorney of record.