(CNN) -- Police looking for a 5-year-old Illinois boy reported missing from his home say they're putting special focus on the residence after determining it's likely he neither was abducted nor walked away.
The boy's parents reported Andrew "AJ" Freund missing Thursday morning, telling police they last saw him around 9 p.m. the evening before, at bedtime, according to a release by the Crystal Lake Police Department.
The search has included 15 police agencies, drones, and rescue canine units. Sonar teams that searched Crystal Lake located nothing, and the canine teams "only picked up Andrew's 'scent' within the residence indicating that Andrew had not walked away on foot," the police said.
"(T)here is no indication that would lead police to believe that an abduction had taken place," the department said in the release.
The Illinois Department of Children and Family Services has "been involved with the family" since Andrew's birth, department spokesman Jassen Strokosch told CNN. Andrew "was brought into care with us" soon after he was born, when "neglect was indicated on part of the mom," Strokosch said. From 2013 to 2015, the infant was "in care with someone else," he said.
The department was called in twice in 2018 on allegations of neglect in March and of abuse and neglect in December, Strokosch said. The allegations were determined to be unfounded in both instances, he said.
A younger sibling who had been in the home until this week is now living with another family, Strokosch said.
JoAnn Cunningham, Andrew's mother, "doesn't know what happened to AJ, and had nothing to do with the disappearance of AJ," her attorney, George Kililis, told reporters, CNN affiliate WLS reported. "Ms. Cunningham is worried sick. She is devastated."
"AJ, please come home," his father, Andrew Freund Sr., said to television cameras. "We love you very much. You're not in any trouble. We're just worried to death. Please, please come home."
Crystal Lake police issued a press release with Andrew's description Thursday but didn't issue an AMBER alert "due to law enforcement being unable to confirm an abduction occurred," the department said.
Police said about 373 acres were searched on foot, and almost 500 acres were searched by drones. A sonar team searched under docks and piers along all of Crystal Lake and in the lake close to the main beach area, a release said.
Police "are continuing to actively investigate," the department said Friday.