The stepmother of a missing Indiana girl is facing murder charges after the 10-year-old's body was found in a shed behind the family home.

Police in Gas City, Indiana, had been searching for Skylea Carmack since her stepmother,  Amanda Carmack, 34, reported her missing Saturday night. Police found the body Wednesday wrapped in a plastic garbage bag inside the shed.

Carmack was charged with murder, neglect of a dependent resulting in death, domestic battery resulting in death and strangulation.

“In law enforcement, our main focus is who and how, not why,” Indiana State Police Sgt. Tony Slocum told a press conference. “Trying to rationalize why someone would kill a 10-year-old? There's no rationale for that. That's just an act of cowardice.”

Carmack’s stepmother originally reported the girl had run away, prompting a days-long search by police and a statewide state police alert.  Police said they feared she was “in extreme danger and may require medical assistance.”

A state police press release confirmed the girl likely was strangled. Investigators said it likely happened between 4:30 p.m. and 6 p.m. Saturday. 

Her father, Kevin, was ruled out as a suspect. He told WXIN, the Indianapolis Fox affiliate, he was at work when his daughter disappeared.

Amanda Carmack was booked into Grant County Jail early Wednesday as police continued investigating.

Police Scene Representational image of a crime scene. Photo: Suzanne Cordiero/AFP/Getty Images