A man, identified as Drew Atchison, was charged Monday in a triple homicide case in rural southeast Missouri. The 24-year-old from Williamsville faces three counts of first-degree murder, armed criminal action, and child kidnapping.

Authorities identified the victims as Samara Fontaine Kitts, 23, her boyfriend Harley Michael Million, 24, and their 17-month-old daughter Willa Fontaine Million.

According to court documents by CBS-affiliated KFVS-TV, Atchison confessed to the killings but the motive behind it was not listed in the documents. Autopsies of the three victims were set for Tuesday in Farmington, Missouri.

The Wayne County Sheriff’s Office, Butler County Sheriff’s Office, Missouri State Highway Patrol, DDCC and Highway Patrolman are investigating the case.

Deputies said Atchison fatally stabbed the adults Thursday at their home in Wayne County and later put the bodies in the back of the family's truck. He allegedly left the toddler alone overnight, locking her in a room with dogs.

The following day he returned to the home to destroy the evidence of his crime, according to court documents. Atchison took the child with him as he drove the family's truck to the neighboring Butler County. The documents said he threw the knife used in the killings in the woods.

Atchison fatally shot the child and buried her with her parents, the court document said. The bodies of the victims were found on a private property in Butler County on Monday, a day after relatives alerted police that the family went missing.

When deputies arrived at the home, they found evidence at the rear of the home that indicated a possible homicide, court documents said.

Crime Tape
A representational image of a crime scene. Getty Images/ Christopher Furlong

Kitts and Million weren’t married but had been together for eight years and were “amazing parents to Willa,” a relative of the victims said in a statement.

"They were a loving family and amazing parents to Willa. They weren't married, but they had been together for the last eight years, since high school. They both have large families who love them very much and a large circle of life-long friends," the family member said in the statement about Harley and Samara on Monday.