Someone got to them when they were vulnerable.

Write down the timeline while you remember it. When was the diagnosis? When did the beneficiary move in, take over the finances, or start driving to appointments? When was the document signed, and who arranged it? Undue influence cases are built on sequences.

Gather what you have: texts and emails from the period, photographs, calendar entries, and the names of anyone who visited. Medical records, the drafting lawyer's file, and bank records will be subpoenaed later, but the family's own evidence about how the person was doing is often what makes the story clear.

The claim itself is brought as part of a trust contest, a will contest, or a petition to set aside a deed or gift. Where the beneficiary is a caregiver or drafter, the section 21380 presumption shifts the burden to them. Where money or property has already been taken, a financial elder abuse claim and a Probate Code section 850 petition can be filed alongside.

Undue influence and lack of capacity are grounds, not separate lawsuits, so the deadline follows the document you are challenging. A trust amendment has to be contested within 120 days of the trustee's notice. A will has to be contested before it is admitted to probate or within 120 days after. A financial elder abuse claim based on the same facts runs four years from discovery, and a claim against a person who has died generally has to be filed within one year of death.

Evidence in these cases also has a shelf life. Medical providers purge records, phone carriers keep texts for a limited time, and the people who saw what happened move away or forget.

We start by mapping the relationship: who had access, who had authority, and when the balance changed. Then we get the records that show the person's condition on the day the document was signed, which usually means the primary care chart, hospital and pharmacy records, and any neuropsychological testing.

The drafting lawyer's file matters as much as the medical chart. Notes from the meeting, who was present, who paid, and whether the lawyer met with the person alone. We subpoena it early. We also look for the pattern of isolation and control that the statute describes: changed locks, changed phone numbers, a caregiver who answers every call.

Cases are filed in Santa Clara County Superior Court in San Jose, or in the county where the trust or estate is being administered. We use Legion, the AI litigation platform our founder co-founded, to go through the medical and financial records quickly, and we retain a geriatric psychiatrist or neuropsychologist when the capacity question calls for medical testimony.

It happens more often than families expect. The helper who came three days a week becomes a spouse, sometimes in a courthouse ceremony nobody heard about until later. Undoing the marriage itself is hard. The law asks very little of a person before letting them marry, and once a parent has died, an annulment for lack of mental capacity is no longer available to anyone.

In 2019 California changed the law so that families no longer have to undo the marriage. Since January 1, 2020, a gift or estate plan change made for a caregiver spouse within six months of the wedding is presumed to be the product of fraud or undue influence, and a caregiver whose spouse died within six months of the wedding is presumed not to be entitled to a spouse's share of the estate. The caregiver has to prove otherwise by clear and convincing evidence, and on a gift pays the other side's fees if they cannot.

The six-month windows are what make these cases, so the dates of the care, the marriage, any new document, and the death matter from day one. We explain the details, and what can be done while a parent is still alive, in A caregiver married my parent: what California law allows.

• Dad signed a new trust six weeks after his dementia diagnosis, and the new beneficiary drove him there. Vulnerability, authority, and haste, in one sentence. That is the fact pattern the statute was written for.
• Mom's caregiver is now on the deed to her house. A transfer to a paid care custodian is presumed to be the product of fraud or undue influence, and the deed can be set aside through a section 850 petition.
• A sibling took over the finances and the parent stopped talking to everyone else. Isolation and control of information are named tactics in the undue influence statute.
• A parent with capacity made a choice the family hates. That is allowed. The law protects free choices, including unfair ones. The question is always whether the choice was free.