Investigators have found what they believe to be the body of a 5-year-old boy who went missing from his suburban Chicago home nearly a week ago. Remains police believe are those of Andrew "AJ" Freund were found wrapped in plastic in a shallow grave in a remote area of Woodstock, Illinois, about seven miles from the boy's home, Crystal Lake police chief James Black said Wednesday.

Both of the child's parents have been charged with murder, battery and other counts and were ordered held on $5 million bail each during Thursday morning court appearances, reports CBS Chicago.

The boy was reported missing from his Crystal Lake home by his father April 18. In a 911 call released Tuesday, the boy's father Andrew Freund Sr. claimed he last saw the boy when he went to bed the night before. The elder Freund, 60, said the boy was missing when he returned home the next morning from an early doctor's appointment.

Andrew "AJ" Freund Handout

But during interviews early Wednesday with Crystal Lake police and the FBI, Black said Andrew Freund Sr. and the child's mother JoAnn Cunningham, 35, were confronted with forensic analysis of cellphone data developed by investigators. Both then provided information that led to the recovery of the body, Black said.

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Criminal complaints allege that each parent on April 15 forced the boy to remain in a cold shower for an extended period of time and then struck the boy on his body, "knowing that said acts created a strong probability of death of death or great bodily harm."

A complaint for Cunningham also alleges she struck the boy on March 4, and a complaint for Andrew Freund Sr. alleges he buried the child's body.

An official cause of death has not yet been released by the McHenry County Coroner's office.

"To AJ's family, it is my hope that you may have some solace in knowing that AJ is no longer suffering, and his killers have been brought to justice," Black said after their arrests Wednesday. "I would also like to thank the community for their support and assistance during this difficult time. To AJ, we know you're at peace playing in heaven's playground and are happy that you no longer have to suffer."

Cunningham is charged with five counts of first-degree murder, four counts of aggravated battery, two counts of aggravated domestic battery and one count of failure to report a missing child or child death.

The elder Andrew Freund has been charged with five counts of first-degree murder, two counts of aggravated battery, one count of aggravated domestic battery, two counts of concealment of a homicidal death and one count of failure to reports a missing child or child death.

Cunningham, who is seven months pregnant, appeared to be fighting back tears in court as prosecutors detailed the charges, CBS Chicago reported.

Andrew Freund, Sr., left, and JoAnn Cunningham, the parents of slain boy AJ Cunningham, depicted in a sketch from a Thursday court appearance Sheryl Cook

Investigators were seen at the family's home Wednesday removing a shovel, the mattress from a child-sized bed, several large bags and a large plastic bin, and loading them into an evidence team van, according to the station.

On Tuesday, the department released more than 60 pages of police reports written by officers who responded to various calls about the house, which is about 45 miles northwest of Chicago. The reports indicate officers visited the family's home 10 times over the past five years, often noting the poor condition of the home, according to CBS Chicago.

One report described seeing the home littered with dog feces and urine, and a children's bedroom where "the smell of feces was overwhelming." Another report said the officer found the house to be "cluttered, dirty and in disrepair," and without electrical power.

The heavily-redacted reports also indicate state child welfare workers were called after officers spotted a large bruise on one of the young boys living there in December, but that the children appeared to be "healthy and happy" and were not removed from the house. Cunningham said the bruise "must have been from the dog."

Prior to their arrests on criminal charges, Cunningham and Freund appeared in court Tuesday seeking custody of their 4-year-old son, Parker. Parker was taken into custody by the Illinois Department of Children and Family Services on Thursday after AJ was reported missing by his parents.

JoAnn Cunningham, left, and Andrew Freund Sr., right Crystal Lake police via CBS Chicago

In a statement released to CBS Chicago, DCFS acting director Marc Smith called the news of AJ Freund's death "heartbreaking." DCFS had contact with the family since AJ was born with opiates in his body in 2013. The Northwest Herald said he was in foster care for two years before being returned to his parents.

"Protecting vulnerable children who come to our attention is at the core of our mission at DCFS," Smith said. "All of us feel this loss. our priority is the care and safety of Andrew's younger sibling."

Smith said the department would conduct a "comprehensive review of the entirety of our work with Andrew's family to understand our shortcomings and be fully transparent with the public on any steps we are taking to address the issues."

Gov. J.B. Pritzker in March ordered an independent review of DCFS after the deaths of a 2-year-old girl in Decatur and a 2-year-old boy in Chicago. Child welfare workers had contacts with both families.