Short answer

Yes. Under Illinois law you can challenge transfers an agent made under a power of attorney (POA) if you have a good-faith basis to believe the principal (for example, your grandfather) lacked the mental capacity required when the POA was signed or when the transfers were made. Challenges typically proceed as civil claims for lack of capacity, breach of fiduciary duty, undue influence, fraud, or conversion. In urgent cases you can also seek emergency court relief to stop ongoing transfers or freeze assets.

Detailed answer — how a challenge works in Illinois

1. What “capacity” means for a power of attorney

To create a valid power of attorney in Illinois, the principal must have sufficient mental capacity to understand the nature and consequences of the document and the transaction at hand. That generally means the person must understand who they are appointing, the powers they are granting, and the likely effects on their property and affairs. If the principal did not understand those things when they signed the POA (or lacked the ability to form a rational decision when transfers occurred), the document or specific transfers can be attacked as invalid or voidable.

2. Legal theories you can use to challenge transfers

• Lack of capacity: Argue the principal did not have the required mental capacity when the POA was signed or when the agent made the transfers.
• Undue influence: Show the agent or third parties pressured, coerced, or manipulated the principal into signing the POA or authorizing transfers.
• Breach of fiduciary duty: Agents owe duties (loyalty, prudence, to avoid self-dealing). Improper transfers for personal benefit can be reclaimed.
• Fraud or forgery: If the signature or documents were forged or the agent misrepresented facts to obtain the POA or transfers.
• Conversion or unjust enrichment: Seek return of wrongfully transferred assets.

3. Typical court actions and remedies

You or another interested person may file civil claims in Illinois court seeking one or more of the following remedies:

• Declaratory judgment that the POA or particular transfers are void or voidable;
• Monetary damages to recover assets taken from the principal;
• Accountings and disgorgement of funds the agent spent improperly;
• Temporary or permanent injunctions freezing assets, preventing further transfers, or restraining the agent;
• Appointment of a guardian or conservator if the principal is currently incapacitated (this is a separate proceeding under Illinois guardianship law).

4. Evidence courts look for

Common and persuasive forms of evidence include:

• Medical records and physician or neuropsychological reports documenting cognitive decline around the time the POA was signed or transfers occurred;
• Testimony from family, friends, caretakers, or professionals who observed confusion, memory loss, or impaired decision-making;
• Contemporaneous notes, emails, or recordings showing pressure, poor explanation of terms, or the agent’s control of the principal’s affairs;
• Suspicious transaction patterns (large transfers soon after signing, transfers to the agent, or transfers inconsistent with the principal’s prior financial patterns);
• Notary records, drafts of the POA, or evidence of changes, redactions, or missing pages that suggest tampering.

5. Timing and statutes of limitation

How long you have to bring a claim depends on the legal theory (fraud, conversion, breach of fiduciary duty, etc.). Illinois law sets different time limits for different claims, and some claims may be tolled while misconduct is concealed. Because deadlines can be short and evidence can disappear, act promptly — put financial institutions on notice, preserve records, and consult an attorney quickly.

6. Immediate practical steps to protect the principal and preserve claims

1. Secure documents: Make copies of the POA, bank statements, cancelled checks, transfer receipts, and communications about the transfers.
2. Preserve evidence: Ask banks and institutions to freeze or flag accounts if fraud is suspected. Send written demands for an accounting from the agent.
3. Obtain medical records: Request relevant medical or psychiatric records that show the principal’s condition at the time of signing and at the time of transfers.
4. Consider emergency court relief: File for a temporary restraining order or seek appointment of a guardian if the principal is currently at risk or incapacitated.
5. Talk to an attorney experienced in Illinois elder law, probate and fiduciary litigation — they can evaluate your evidence and file appropriate court actions.

7. Who has standing to sue?

Interested persons typically include close family members, beneficiaries, or anyone who can show a financial or legal interest in the principal’s estate. Illinois courts will consider claims brought by family, prospective heirs, or parties harmed by the transfers.

8. Guardianship vs. POA challenge

Challenging a POA is a separate civil claim from a guardianship (now commonly called a “plenary guardian/conservator” under Illinois law). If the principal is presently incapacitated, you can petition the probate or circuit court to appoint a guardian who can manage the person’s affairs and undo improper transfers through the guardian’s legal authority.

9. Criminal options

In some situations, financial exploitation of an elderly or disabled person can be a crime. You may report suspected theft or exploitation to local law enforcement or the state attorney’s office. Criminal investigations and prosecutions operate independently of civil claims and may result in restitution or other penalties.

Relevant Illinois law (where to look)

Key Illinois law and resources you should review or ask your attorney about include the Illinois statutes and rules that govern powers of attorney, fiduciary duties, probate and guardianship, and elder abuse. The Illinois General Assembly maintains the Illinois Compiled Statutes online: https://www.ilga.gov/legislation/ilcs/ilcs.asp. For court forms and guardianship procedures consult the Illinois Courts at https://www.illinoiscourts.gov.

Hypothetical example (illustrative)

Suppose your grandfather signs a durable power of attorney naming his caregiver as agent. Two weeks later, the agent transfers $150,000 from your grandfather’s savings into the agent’s account and writes checks for personal expenses. Your grandfather’s primary care physician documented memory problems and confusion a month before the POA was signed. Family members noticed your grandfather could not consistently name family members or describe his assets at the time of signing.

In that situation you could: (1) demand an accounting from the agent; (2) ask the bank to freeze suspicious transfers or place a hold while you investigate; (3) obtain the grandfather’s medical records to show capacity issues; (4) file a civil suit alleging lack of capacity, breach of fiduciary duty and conversion; and (5) consider asking the court for emergency relief and appointment of a guardian to protect remaining assets.

Helpful hints — quick checklist

• Act quickly. Preserve bank records, the POA document, and medical records immediately.
• Demand a written accounting from the agent as soon as you suspect misuse.
• Document observations: who saw what, when, and where. Contemporaneous notes help credibility.
• Talk to the bank. Many banks will investigate suspicious POA activity or flag accounts.
• Get a copy of the POA including any attachments and notarization details (notary name, county, date).
• Collect independent witnesses who can testify to the principal’s mental state at the relevant time.
• Consider both civil and criminal options — report suspected exploitation to law enforcement or adult protective services.
• Consult an Illinois attorney experienced with elder law, probate litigation, and fiduciary disputes as soon as possible.