Disclaimer: This information is educational only and is not legal advice. If you are considering challenging a will or defending one, consult a licensed Michigan probate attorney promptly.

Detailed Answer

Overview — who bears the burden and what courts look for

When someone asks a Michigan probate court to invalidate a will because the testator lacked capacity or was subject to undue influence, the person making the challenge (the contestant) must present evidence to convince the court. Courts evaluate two related issues separately:

• Testamentary capacity: whether the testator had the mental ability to make the will at the time it was signed.
• Undue influence: whether another person exerted such pressure, control, or manipulation that the will reflects that person’s intent rather than the testator’s free will.

What Michigan law says about validly executed wills

Michigan law sets out formal requirements for a valid written will (for example, signatures and witness requirements). A will that meets the statutory formalities begins with a legal presumption of validity; a contestant must overcome that presumption with evidence. You can review Michigan’s statutory provisions about execution of wills here: MCL §700.2502 (Execution of wills).

What constitutes testamentary capacity in Michigan

To have testamentary capacity a testator generally must, at the time the will was made, understand:

1. the nature and effect of making a will (that the document disposes of property at death);
2. the nature and extent of the testator’s property; and
3. the natural objects of the testator’s bounty (who the testator’s close family or usual beneficiaries are) and how the will disposes of property among them.

Evidence that bears on capacity includes medical and mental-health records, testimony from treating physicians or caregivers, contemporaneous notes or statements by the testator, the testator’s behavior near the time of signing, and cognitive test results (e.g., MMSE scores) if available.

What constitutes undue influence

Undue influence exists when someone exerts pressure or domination over the testator that overcomes the testator’s free will and causes the testator to sign a will reflecting the influencer’s wishes rather than their own. Courts examine the totality of circumstances; there is rarely one single piece of proof that decides the issue.

Types of evidence that are most persuasive

Below are common, persuasive categories of evidence for each claim.

Evidence of lack of testamentary capacity

• Contemporaneous medical records showing dementia, delirium, stroke, severe psychiatric illness, or medication effects that impair cognition.
• Physician, psychologist, or psychiatrist testimony saying the testator lacked capacity at the time the will was executed.
• Documentation of cognitive testing performed close in time to signing.
• Testimony from family, caregivers, or friends describing confused speech, memory loss, inability to understand finances, or unusual behavior near the signing date.
• Evidence of heavy sedation, intoxication, or acute illness at the moment of signing.
• Handwriting analysis showing signatures by someone other than the testator (in cases of forgery) or evidence the testator could not physically sign without assistance that masked incapacity.

Evidence of undue influence

• Relationships and opportunity: proof that the beneficiary controlled access to the testator (isolated the testator from family, handled doctor visits, controlled visitors).
• Susceptibility: evidence the testator was dependent, ill, elderly, or cognitively vulnerable.
• Actions by the beneficiary: who drafted or procured the will, who paid for the attorney, or who was present and insisted during the will execution.
• Timing and suspicious circumstances: a sudden, unexplained change from an earlier will or testamentary plan that favored a caregiver or newcomer.
• Statements or admissions by the alleged influencer suggesting control or pressure.
• Destroying or hiding earlier wills, or removing family members from participation.
• Financial records showing large transfers, unexplained gifts, or a beneficiary spending the testator’s funds before death.

How courts combine the evidence

Courts weigh the quality and timing of evidence. Contemporaneous medical records and testimony from treating clinicians are highly persuasive. Corroborated witnesses who saw the testator’s state at signing strengthen a contestant’s case. Evidence of suspicious circumstances (e.g., the beneficiary procured the will, drastic change in terms) often triggers closer judicial scrutiny. A validly executed will is presumed valid, so the contestant must present sufficiently strong proof to overcome that presumption.

Practical examples (hypotheticals)

Example A — Capacity: A 90-year-old with a recent diagnosis of advanced Alzheimer’s disease signs a new will. Hospital notes from two days earlier report severe confusion and inability to state family members’ names. A neurologist testifies the testator lacked capacity that day. This combination (medical records + expert testimony) is powerful evidence of lack of capacity.

Example B — Undue influence: A caregiver moved an elderly person into a private room, refused family visits, drafted a will naming herself as sole beneficiary, paid for the attorney, and was the only witness at execution. Family testimony about isolation and the suspicious change in beneficiaries, together with records showing the caregiver arranged the will, creates a strong undue influence claim.

Procedural and timing considerations

Time matters. Evidence erodes over time; medical records can be lost and witnesses’ memories fade. If you suspect undue influence or incapacity, preserve medical records, collect witness names and contact information, and seek legal advice promptly. Probate procedures and deadlines can vary, and formal challenges usually must be filed in the probate court handling the estate.

What a lawyer will often do

A probate attorney will evaluate the available evidence, subpoena medical and financial records, take witness statements, consult medical experts, and file the necessary pleadings to contest the will if warranted. They will also evaluate risks, costs, and the likelihood of success.

Helpful Hints

• Act quickly: preserve medical charts, appointment notes, medication lists, financial records, and any documents or earlier wills.
• Write down what witnesses remember while memories are fresh: dates, who was present, exact words heard at signing, and unusual behavior.
• Obtain a copy of the will and any prior wills if possible; compare changes and dates.
• Gather proof of who arranged or paid for the will preparation and who was present at execution.
• Collect evidence of isolation or control (phone logs, visitor logs, statements from social workers or care-facility staff).
• Ask a lawyer about expert witnesses (medical or forensic) who can strengthen capacity or undue-influence claims.
• Don’t confront suspects or destroy evidence; preserve documents and let your attorney handle communications.
• Remember: an informal distrust or dislike of a beneficiary is not enough; courts need concrete evidence of incapacity or overpowering influence.