The Sheriff’s Department said late Sunday the coroner’s office determined the girl was 9-year-old Trinity Love Jones and her death was ruled a homicide.
The cause of death is being withheld, however.
The two people detained are described as persons of interest. Their names have not been released.
Trinity’s body was found partly protruding from the duffel bag on March 5 in an unincorporated area of Hacienda Heights, southeast of Los Angeles.
A sketch of the girl was released to help identify her.
The Sheriff’s Department says she was a resident of Los Angeles County.