In Undue Influence in Making Bequests: A Forensic Psychiatrist Examines the Evidence, undue influence expert witness Stephen M. Raffle, M.D., writes:
One of the inferences for the exertion of “undue” influence is if a close or isolative relationship existed between the testator and the proponent of the changed will or trust at the time changes are entered into. When the beneficiary/caregiver isolates the testator from his/her other natural heirs, there is an index of suspicion to the psychiatrist for undue influence.
Another circumstantial fact may be a financial relationship between the “favored” beneficiary and the testator. For example, the favored beneficiary has check-writing authority and is otherwise being empowered to take over the financial affairs of the testator. Yet other example may be the receipt of a joint tenancy interest in real property even though the property was paid for entirely by the testator, or being employed by the testator’s business (or promoted if already an employee) up to and including being made an officer of the company.