This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.As homicide detectives searched a landfill in Victorville on Monday for the body of a missing 6-year-old boy who is presumed dead, prosecutors charged his mother and aunt with murder. Investigators believe that Duke Flores’ remains were placed in a dumpster at some point after he was killed, according to the San Bernardino County Sheriff’s Department. In addition to detectives, sheriff’s volunteers and landfill personnel are also assisting in the search for Duke’s body. Meanwhile, boy’s mother, 29-year-old Jackee Racquel Contreras, and her twin sister, Jennifer Rachel Contreras, have each been charged with one count of murder, the San Bernardino County District Attorney’s Office announced on Monday afternoon. Both were arrested on suspicion of murder over the weekend. Their arraignments are scheduled to take place Tuesday; each is being held without bail. Apple Valley police officers discovered the child had been missing after they went to a home in the 22000 block of Cherokee Avenue last Thursday to perform a welfare check requested by relatives, according to the Sheriff’s Department. Jackee Contreras told police her son had last been seen more than a week earlier, investigators said. She was taken into custody for not reporting that Duke was missing. Authorities searched the area, but could not find the child. The following day, Apple Valley Police Department officials issued a public plea for help finding the missing boy, whose last known location was in the area of Cherokee Avenue and Pawnee Road. At a vigil Friday night, family members told KTLA that Duke has autism and had wandered away from home in the past. His grandmother, Lydia Gutierrez, said she hadn’t seen her grandson in 10 days. Authorities have remained tight-lipped about what evidence they have to indicate the boy was killed. The search was suspended at around 5:00 p.m. after detectives, volunteers and canines searched through the landfill that contains about 600 tons of garbage, according to the Sheriff’s Department. Officials said the search was expected to resume Tuesday. Anyone with information about the case is urged to call Detective Narcie Sousa at 909-387-3589 or sheriff’s dispatch at 909-387-8313. Anonymous tips can also by calling the We-Tip hotline at 800-78-CRIME or by going to the website www.wetip.com. KTLA’s Nouran Salahieh contributed to this report.