Police find body of missing 5-year-old Andrew 'AJ' Freund, charge parents with murder Andrew "AJ" Freund was reported missing on April 18.

Police believe they have found the body of missing 5-year-old Andrew "AJ" Freund, one week after he vanished from his Crystal Lake, Illinois, home, police said Wednesday.

After police presented AJ's mother and father with cell phone evidence, the parents gave information that led investigators to a body believed to be that of the little boy, Crystal Lake Police Chief Jim Black said at a news conference on Wednesday.

The body was buried in a shallow grave, wrapped in plastic, in a rural area near Woodstock, Illinois, Black said.

Both parents, Andrew Freund Sr. and JoAnn Cunningham, are being charged with his disappearance and death, Black said. Charges against them include five counts each of first-degree murder, Black said.

Speaking directly to AJ, Black said, "We know you're at peace, playing in heaven's playground."

His cause of death is not clear, Black said.

AJ was reported missing by his mother on April 18, according to her attorney, George Kililis.

Crystal Lake police said on Monday that AJ's mother was being "uncooperative" with investigators.

However, Kililis told "Good Morning America" over the weekend that when Cunningham reported AJ missing, she spoke with multiple officers and "was fully cooperating."

Kililis said he got the impression that police considered Cunningham a suspect, so he told her to remain silent.

"She has nothing to do with his disappearance," Kililis said over the weekend. "She's nothing more than a grieving mother."

As police spent the week scouring the area, they said there was no indication the boy was abducted.

Canine teams only picked up the boy's scent within his home, which police said indicated he didn't walk away on foot. Crystal Lake is about 50 miles northwest of Chicago.

During the search, AJ's younger brother was placed in a different home under a Department of Children and Family Services (DCFS) safety plan, a DCFS spokesman told ABC News earlier this week.

DCFS has been in contact with AJ's family since he was born with opiates in his system in October 2013, DCFS said.

AJ was taken into protective custody and placed in foster care in November 2013, DCFS said. He was returned to his home in June 2015, according to the agency.

In March 2018, DCFS officials investigated allegations of neglect by AJ's parents; the allegations were unfounded, according to DCFS.

The last contact between DCFS and the family was in December 2018, after Cunningham called the cops to report that AJ's father stole her cellphone and medication.

Responding police found dog feces and urine in the family's home. Officers also found a bruise on one of the children, but were "unable to make a determination of abuse," and released the kids back to the parents, according to police reports. Child protection staffers investigated the allegations of abuse and neglect, but the allegations were unfounded, a DCFS spokesman said.

The news of AJ's death is "heartbreaking," Marc Smith, acting director of Illinois DCFS, said in a statement Wednesday.

"Our priority is the care and safety of Andrew's younger sibling," Smith said. "We will continue to cooperate with law enforcement in their ongoing investigation. The Department is committed to conducting a comprehensive review of the entirety of our work with Andrew's family to understand our shortcomings and to be fully transparent with the public on any steps we are taking to address the issues."

ABC News' Whitney Lloyd and Henderson Hewes contributed to this report.