I am not sure that you are posting your question in the right section. This issue would probably better addressed by a civil attorney, perhaps even a probate attorney. Given that you haven't listed any instances of your sibling using force or threatening you I don't know that there are any facts to support a claim of extortion. As to your other question, "has he committed any other offense" - that's really kind of vague, similar to asking how long is a piece of string? Don't forget you have posted your question in a forum where criminal defense attorneys respond... maybe if there's a prosecutor lurking on the forum they could give you some insight as to any other potential offenses. I hope you are able to resolve your differences with your sibling without the need to involve the authorities. Good luck to you.
This answer is for general informational purposes only and shall not constitute legal advice. I have answered a question on a public forum which does not establish any attorney-client relationship. For a more detailed legal analysis you should consult with a legal professional in your area.
I agree with Mr. Keating. You need to address this question to a civil attorney with experience in property law and/or wills & estates law.
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