FLINT, MI -- A father who was accused of killing his 3-year-old daughter and burying her body has reached a plea agreement and agreed to testify against the girl's mother.

Khairy Joshuawon Simon pleaded guilty to second-degree murder and removing a dead body without permission of the medical examiner on Tuesday, June 12, before Genesee Circuit Judge Geoffrey L. Neithercut.

Simon, 27, admitted to killing his daughter Kimora Lee Simon in 2015 and investigators believe he put her body in a backpack and buried her along railroad tracks near the Evergreen Regency apartments.

The girl's mother, Erika Shantae Finley, also is charged in connection to the killing.

"We felt that she was more complicit in the abuse, neglect and in the death of the child and the cover-up," Genesee County Prosecutor David Leyton said of Finley. "He has shown remorse and a willingness to cooperate."

Simon will testify against Finley, Leyton said, and the Genesee County Prosecutor's Office won't object to a sentence on the low end of the sentencing guidelines.

Leyton said Simon could face between 13.5 years to life in prison when he is sentenced on July 11.

Police believe the parents killed the girl together and that the father buried her, MLive-The Flint Journal previously reported.

Investigators started asking questions about Kimora Simon when the Michigan Department of Health and Human Services was investigating potential abuse of her brother.

A DHHS employee visited Finley's home at Evergreen Regency and asked Finley where Kimora Simon was, MLive-The Flint Journal previously reported.

Finley told police the child was with her father, Khairy Simon, in Detroit, but he provided a conflicting story regarding the child's whereabouts, Leyton previously said.

Relatives had not seen the child in more than a year and Khari's girlfriend said she'd never seen the child once in the eight months they'd been together.

Along with the parents' conflicting stories, Leyton also noted in 2015 that "other information gleaned" led investigators to believe Kimora was dead and buried along the railroad tracks near Evergreen Regency.

Her body has never been recovered. Investigators believe the child was taken from the grave by animals.

Finley will be back in court on Thursday, June 14.