Legal Question in Wills and Trusts in Illinois

In Illinois, a person is legally presumed to be alive for at least seven years after their disappearance. If there is evidence indicating they are not alive, i.e. last seen screaming for help before the landslide hits, the period can be shortened. There's an excellent article with annotations to Illinois law in a Chicago Tribune article by Eric Zorn dated November 29, 2007 discussing the foregoing. The person seeking to have the disappeared person declared dead has some duty to actively seek the whereabouts of the disappeared person.

As attorney Prihoda notes, there is a procedure for a probate court to declare an individual deceased based upon a presumption of death.

It should be noted though that if your brother is declared deceased, then his share of your mother's estate would be released to the administrator of your brother's estate. Your brother's estate would then pass through his estate according to his will, if he had one, or if no will then to your brother's legal heirs. For example, if he left a surviving spouse and/or children/descendants, they would be his heirs. If he left no spouse or descendants, then his heirs would be his parents, siblings and descendants of deceased siblings.

Talk to a probate attorney directly about the process. If it has been less than 7 years since he was last seen, then more proof of death will be needed.