Quick overview

When someone challenges a will in New Jersey, the challenger must show why the court should not admit the will to probate. Two common grounds are undue influence and lack of testamentary capacity. Courts look at the testator’s mental state, the circumstances around the signing, and any suspicious patterns that suggest someone else controlled the testator’s decisions.

What the law requires (general statutory context)

New Jersey wills and probate are governed by the State’s probate laws (Title 3B). The statutes set out formal requirements for execution of a will and govern probate procedure. For general statutory background on wills and estate administration in New Jersey, see the New Jersey Legislature and court resources:

• New Jersey Legislature (search Title 3B – Administration of Estates)
• New Jersey Courts — Self-Help: Wills, Estates & Probate

Types of evidence that help prove undue influence

Undue influence generally requires showing that a third party exerted pressure or control that overcame the testator’s free will and produced a will reflecting the influencer’s wishes rather than the testator’s. Useful evidence includes:

• Relationship and access: proof the challenger had a confidential or dominant relationship with the testator (caregiver, close friend, paid attendant, or someone with control over daily life).
• Opportunity and presence: testimony or records showing the suspected influencer was present or had unsupervised access when the will was prepared or signed.
• Suspicious circumstances around execution: sudden or unexplained changes to a prior will or estate plan, secrecy about the new will, a short time between meeting an attorney and execution, or the influencer arranging or paying for the lawyer or will execution.
• Unnatural dispositions: a will that sharply favors the influencer while cutting out close family with no clear reason.
• Active procurement: evidence the influencer arranged the will signing, selected the attorney, or coached the testator on what to say or sign.
• Isolation and control: communications or testimony showing the influencer isolated the testator from family or friends, controlled visits, controlled mail or finances, or used threats or persuasion.
• Contemporaneous communications: emails, texts, voicemail messages, letters, or notes that show pressure, instruction, or attempts to control the testator’s decisions.
• Financial records: bank statements, transfers, ATM withdrawals, or documents showing the influencer benefited financially close to the will change.
• Witness testimony: affidavits or testimony from witnesses to the signing, caregivers, neighbors, or medical staff who noticed changed behavior or undue control.
• Documents showing manipulation: power of attorney forms, deeds, or medical directives that were changed around the same time and that appear to benefit the same person.

Types of evidence that help prove lack of testamentary capacity

To prove the testator lacked the mental capacity to make a will, evidence generally must show the person did not understand the nature and consequences of making a will at the relevant time. Helpful evidence includes:

• Medical records and diagnoses: physician and hospital records showing dementia, delirium, severe mental illness, intoxication, or conditions that impair cognition near the time the will was made.
• Treatment notes and evaluations: progress notes, cognitive testing (MMSE, MoCA), psychiatric evaluations, or neuropsychological testing that document impaired memory, judgment, or understanding.
• Medication records: prescriptions and dosing that could cause confusion, sedation, or impaired judgment (e.g., high-dose opioids, benzodiazepines, anticholinergics).
• Witness accounts: testimony from the attorney who prepared the will, the attesting witnesses, family members, caregivers, or others who saw the testator’s mental state at the signing (slurred speech, confusion, inability to grasp relationships or assets).
• Testator’s statements and behavior: contemporaneous writings, recorded conversations, or behavior that show the person did not understand who would benefit or the extent of their property.
• Prior wills and consistency: comparison of the challenged will with earlier wills; erratic, inconsistent changes can support a lack of capacity claim when combined with other proof.
• Timeline evidence: timing between a medical event (stroke, head injury, infection) and the will’s execution can be persuasive when capacity was doubtful immediately after the event.

How courts evaluate the evidence

Courts weigh all relevant factors. Typical court considerations include:

• Whether the testator knew the nature and effect of making a will (that it disposes of property on death).
• Whether the testator understood the extent of their property and who the natural beneficiaries would be.
• Whether the testator was free from undue influence, coercion, or fraud at the time of signing.
• Whether suspicious circumstances exist (sudden changes, secrecy, or a beneficiary’s active role in procuring the will).

Evidence is strongest when multiple independent sources (medical records, neutral witness testimony, and contemporaneous documents) point the same way.

Practical steps to preserve and gather evidence

1. Immediately preserve original will documents and any earlier wills. If you do not have originals, note who holds them (attorney, bank, safe deposit box) and obtain copies.
2. Get medical records and medication lists for the period around the will signing. Ask the testator’s treating providers and hospitals for complete records and notes.
3. Collect communications: emails, texts, social media messages, voicemail, and letters involving the testator and the suspected influencer.
4. Secure witness statements or affidavits from anyone who saw the testator’s condition or the circumstances of the signing (attorney, witnesses, caregivers, neighbors).
5. Gather financial records showing transfers, gifts, or unusual withdrawals before or after the will was made.
6. Document the chain of events and timeline: when the testator first met the influencer, when the will was changed, and any related events (hospitalizations, new caregivers).
7. Consider forensic evidence where appropriate: handwriting analysis or video/audio evidence may help if forgery or coercion is suspected.
8. Keep careful notes of your information-gathering steps, including dates you requested records and who you spoke with.

What to expect if you file a will contest

A will contest typically starts by filing an objection in the probate court where the will is offered for probate. The court will set a schedule for discovery, evidence exchange, and hearings. Evidence you collected—medical records, witness affidavits, communications, and financial records—will be central to building your case.

Because probate contests can be fact-heavy and procedural, many people hire a probate attorney to handle evidentiary rules, subpoenas for records, and court presentations.

Helpful Hints

• Start collecting evidence early—medical and electronic records can be harder to obtain with time.
• Affidavits from neutral witnesses (attorney, bank officer, hospice worker) are especially persuasive.
• Look for a pattern: one odd fact rarely wins a will contest; multiple, consistent facts strengthen your claim.
• Be discreet: accusations of undue influence are serious; avoid making public claims without legal counsel.
• If you suspect immediate financial abuse, consider emergency steps (freeze accounts, contact the bank, contact the court) with legal help.
• Keep copies of everything you collect and record dates, times, and who provided the material.
• Talk to a probate attorney early to preserve evidence properly (subpoenas, spoliation letters) and understand deadlines and procedural requirements in your county.