You obviously must bite the bullet and hire a probate attorney. It will be expensive. See if you can get him to let you do some of the work and he basically advises you. Do not have him as attorney of record as court appearances will cost you a lot and you can sometimes just write a brief to cover your position. The judge will be biased against you because they do not like people who represent themselves, no matter how intelligent and calm they are. It sounds as though, if your mother did not adopt the stepson, he does not have much of a case. If your parents lived in a community property state, half of his community property automatically passed to your mother; you have to look up your own state's probate laws as to what occurs to the other half, as to whether she gets all of it or just a portion. Her private property [what she owned before their marriage and did not mix ownership with him] remains her property entirely and would pass to you only. It sounds like the attorney and son are trying to take advantage of you. You will want to probate your mother's estate. There are books you can read to see what to do and what the basic law is [see Nolo Press]; that will also help you in cutting down your attorney fees as you will know what you can do on your own. Most probate attorneys will want to handle the entire case so they can earn a lot of money, so you will probably have to interview many. Good luck.
Answered on Aug 17th, 2015 at 5:27 PM