On Tuesday, Lt. Jeff Elston of McLean County Sheriff's Department said the department does not plan to release the details of the investigation or the results of the autopsies to the public.
"Amy (Leichtenberg), Duncan and Jack's mother, does not want to know how her sons died. So, we will not make that information public. If we did, Amy would find out and we intend to protect Amy from this information as is her wish," said Lt. Elston.
Their father, Michael Connolly, was found hanging from a tree.
"Initial indications are that Mr. Connolly did hang himself," said Lt. Elston. Final toxicology tests on Connolly have not been released.
The boys were the subject of an Amber Alert issued on March 10. Officials originally believed the boys, who are from Bloomington, could be in the Chicago area.
Funeral arrangements for the boys are pending, according to a family spokesperson. In lieu of flowers, the family, through a website helpfindduncanandjack.com, is suggesting contributions be sent in the boys' names to The National Center for Missing and Exploited Children. A memorial fund to help with the costs of the funerals has been set up: Duncan and Jack Leichtenberg Memorial Fund, Busey Bank, 301 E. Cedar, St. Leroy, IL 61752.