BIRMINGHAM, Ala. — An 8-year-old boy is being charged with beating a 1-year-old girl to death while they were left home alone as their mothers went to a nightclub, Alabama police said Tuesday.

The boy beat and killed 1-year-old Kelci Devine Lewis when she wouldn’t stop crying, Birmingham police spokesman Sean Edwards said. The mother of the toddler, 26-year-old Katerra Lewis, also is charged with manslaughter, he said.

“This is by far one of the saddest cases that I have witnessed and been a part of since I became a police officer,” Edwards said. “This type of irresponsibility on behalf of a parent is totally unacceptable.”

Police said a murder warrant has been obtained for the boy, who is now in the care of Alabama’s child welfare agency, the Department of Human Resources. His case will go through the family court system. There is no minimum age for prosecution in Alabama, said Tobie Smith, of the Legal Aid Society of Birmingham.

The 8-year-old was the oldest of six children left alone as his mother, who has not been charged or identified, and Katerra Lewis went to a nightclub on Oct. 11, Edwards said.

A woman who answered a call to a number listed for Lewis referred questions to attorney Emory Anthony.

“The only thing I can say at this time is to allow the process to play out,” Anthony said in an email. “I think there will be new information coming out at the hearing.”

A 6-year-old who was in the home told police what happened and the details were consistent with the toddler’s injuries, Edwards said.

Kelci Lewis suffered severe head trauma and major damage to her internal organs, Edwards said. Her body was found in her crib.

“I believe the 8 year-old is going to require some intense counseling for the next several years,” Edwards said. “It’s gonna take some extreme intervention.”

Smith, who is also co-director of the Southern Juvenile Defender Center, said she believes there “are going to be very serious questions about whether an 8-year-old has the rational capacity for the proceedings against him.”

“They’re gonna take a real look at whether maybe this is more a matter of parental culpability than child culpability,” Smith said.

Kim Dvorchak, executive director of the National Juvenile Defense Center, agreed.

“Children themselves are not really designed for a court system, and our court system — even our juvenile court systems — are not designed for very young children,” Dvorchak said.

Katerra Lewis’ Facebook profile photo Tuesday was an image of Kelci that had been printed on the back of a shirt. Another photo posted to her page showed that a fish fry fundraiser had been planned for Oct. 17 to cover Kelci’s funeral costs.

Court documents filed in June show that a judge ordered $388 for child-support payments to be withheld from the monthly income of a man identified as Timothy D. Pope. No one responded to messages left at phone numbers listed for Pope.

Katerra Lewis has posted $15,000 bond and is expected to appear in court Nov. 30, according to court documents.