Estate Law Questions? Ask an Estate Lawyer.
Good Evening. There are several ways to contest the validity of a Will. The first is by proving the person was incapacitated when they executed the document. The second way, is by proving the presence of fraud, forgery, or undue influence. Your friend would have to prove that his mother was unfairly influenced by her husband. The third option is to challenge the execution of the Will. Depending on what state she executed her Will, there are specific rules on how a Will must be executed. If the Will is not executed according to a state's statutes a person can have a Will invalidated.
In order to contest a Will, it is in your friend's best interest to hire an attorney in the state in which his mother's estate will be administered. It is a complicated process and definitely requires the expertise of a licensed attorney.
Hopefully this information will help you guide your friend. Please let me know if you have an additional question or need clarification. I greatly appreciate a positive rating and wish you all the best.