On April 20, 2022, at approximately 6:45 a.m., the Arlington Police Department responded to Cook Children's Hospital in Fort Worth after hospital staff made notification that an infant brought there may be the victim of a criminal offense.

Officers learned that earlier that morning, at around 1:51 a.m., the mother of a four-month-old girl called 911 to report that her daughter was not breathing. An ambulance arrived at their home in the 1000 block of W. Arkansas Lane and transported the baby to the hospital.

The infant, who was publicly identified by the Tarrant County Medical Examiner's Office as Christine Walker, was taken off life support later that morning and was pronounced deceased. 

Doctors indicated her injuries were consistent with physical abuse. The baby's mother, 25-year-old Savannah Johnson-Walker, had also given medical staff and first responders conflicting information about what led to the child becoming unresponsive.

Through subsequent investigation, detectives determined Ms. Johnson-Walker was the baby's sole caretaker and was the only individual alone with the baby prior to her becoming unresponsive.

On June 14, 2023, the Tarrant County Medical Examiner's Office officially ruled the infant's cause of death as complication of blunt force head injury and manner of death as homicide.

In consultation with the Tarrant County District Attorney's Office, detectives obtained a warrant for Ms. Johnson-Walker's arrest on one count of Injury to a Child - Serious Bodily Injury.

She was taken into custody on the warrant on July 6, 2023.

The Tarrant County District Attorney's Office later upgraded her charge to Capital Murder.