Police focused on AJ's parents, Joann Cunningham and Andrew Freund, Sr., early in the investigation. According to the documents, police found a video on Cunningham's phone taken more than a month before his death that showed AJ with bruises to his face and body.
The same documents say Freund, Sr., told police Cunningham searched the term "child cpr" on his phone, which corresponded to searches they found made the night of April 15.
The deputy said police executing a search warrant found a picture of a shopping list on Freund's phone taken on April 17 that included duct tape, plastic gloves, air freshener and bleach, and in the house investigators found a pair of men's shoes with "dripping wet mud" on the bottom. Investigators also found multiple empty bleach bottles in various trash cans.
The affidavit describes the home as having "hoarder like conditions."
Documents obtained by the ABC7 I-Team give an inside look at the Crystal Lake home owned by Joann Cunningham and Andrew Freund, Sr., who are charged with murder in the death of their son AJ Freund.
The pictures, obtained through a Freedom of Information Act request, were taken inside the home in 2013, before and around the birth of their son AJ.
Before his body was found, Crystal Lake police released reports of 17 visits to the home over the last five years, documenting what they called unacceptable living conditions, DCFS concerns for the welfare of the children, and alleged drug use.
A stack of police reports dating back to 2012 detail more than a dozen interactions between Crystal Lake police and Cunningham and Freund. In the span of just a few weeks, police were called to the couple's home for accusations of theft, bad checks, and multiple violent domestic disputes.
Photos taken inside the home show dilapidated and filthy conditions. Police were tipped off by a heating contractor. A police report that matches the photos was written on October 18, 2013, four days after AJ Freund was born.
AJ was taken away from his mother by the Department of Children and Family Services at birth after traces of opiates were found in his blood. He was returned to his parents' custody 18 months later.
Prosecutors said his parents beat him to death and then buried his body. They reported him missing on April 18, claiming they had last seen him in his room around bedtime the night before.
Cunningham and Freund are being held on charges for murder, aggravated battery, aggravated domestic battery, and failure to report the death of their child.
Andrew 'AJ' Freund's foster family releases statement: 'AJ was loved by us'
AJ Freund death: Parents of 5-year-old Crystal Lake boy appear in court Monday
Crystal Lake boy AJ Freund funeral arrangements announced; DCFS releases timeline, 2 workers reassigned
Two child deaths two years apart have DCFS back on hotseat
AJ Freund cause of death released, parents bond set at $5M each for Joann Cunningham, Andrew Freund, Sr.
How did Crystal Lake police crack the case of AJ Freund?
'He got a raw deal and God's going to fix it': Crystal Lake mourns AJ Freund after body found
Missing Crystal Lake boy AJ Freund's body found; parents Joann Cunningham, Andrew Freund Sr. charged
Missing Crystal Lake boy: 911 call reporting Andrew 'AJ' Freund, 5, missing, police history with family released
Missing Crystal Lake boy Andrew 'AJ' Freund: Father continues search, mother pleads for boy's, 5, return
Search continues for missing 5-year-old Crystal Lake boy, father vows own investigation
Crystal Lake community holds vigil for missing boy to "light the way for AJ"
Missing Crystal Lake boy Andrew 'AJ' Freund: Boy, 5, did not leave home on foot, police say
Crystal Lake boy missing: FBI joins search for 5-year-old Andrew 'AJ' Freund