Jonathan P. Kieffer


Phone Number: 816.701.1103

4740 Grand Avenue Suite 300
Kansas City, MO 64112

In Brief

Persuaded the Missouri Supreme Court, en banc, to change a longstanding rule from prior precedents and to require that attorneys now must perform on-line searches during jury selection to determine whether prospective jurors have been involved in prior litigation.

Frequently speaks at local and national professional meetings on topics involving civil litigation

Attorney Jon Kieffer is a Partner with Wagstaff & Cartmell, where he has practiced since 1998. Jon represents individuals and businesses as plaintiffs and defendants in a wide variety of litigation matters in state and federal trial and appellate courts nationwide. His practice includes products liability, professional liability, insurance bad faith litigation and commercial litigation including business torts.

Jon is a Fellow in the International Society of Barristers (ISOB), which includes less than 700 lawyers from the United States, Canada, England, Scotland, Ireland and Australia adjudged by their peers to be outstanding in the field of advocacy. Membership is by invitation only which is preceded by a rigorous screening process that considers the lawyer’s ability, experience, accomplishments and ethical standards as assessed by trial lawyers and judges. One of the ISOB’s principal goals is preservation of the adversary system and jury trial. Jon also was selected by the National Trial Lawyers as one of the Top 25 Product Liability Lawyers in Missouri and he has been named to the Missouri and Kansas Super Lawyers list of litigation attorneys every year since 2009.

Much of Jon’s current practice focuses on automotive, drug and medical device defect litigation, including multidistrict or “mass tort” complex litigation. Several of Jon’s cases have gained national attention. Jon represented the widow and young children of a physician who died after having been given the blood thinner heparin which was found to have been adulterated at a manufacturing facility in China, and the case was featured in the book CHINA Rx – Exposing the Risks of America’s Dependence on China for Medicine. When Jon and the firm filed the first cases on behalf of school districts against electronic cigarette maker JUUL seeking compensation for the youth vaping epidemic in the public schools, the cases were featured in The New York Times, The Washington Post and Good Morning America.

Some results that Jon has obtained on behalf of clients include the following:

Confidential Settlement – Product Liability and Negligence

As lead counsel for two children who were orphaned when their parents were killed in a highway crash, Jon obtained a confidential settlement against U-Haul International and others in a case involving claims of product liability and negligence.

$9 Million Settlement – Wrongful Death Products Liability Case

All details confidential.

$6.7 Million Damages Award – Wrongful Death Case

As lead trial counsel, Jon obtained a $6.7 million damages award.  This award is believed to be the largest compensatory damages award in a wrongful death case reported in Kansas as well as the largest “alter-ego” damages award reported in Kansas, and followed a trial against an oil company and its owners.

$4.7 Million Settlement – Insurance Bad Faith & Defamation

As lead counsel for a couple whose home and contents were destroyed by fire, Jon obtained a settlement in excess of $4.7 million against one of the country’s largest insurance companies after it refused to pay for the fire loss and falsely accused Jon’s clients of insurance fraud. The insurance company ultimately paid more in the settlement than the amount of the original claim after extensive discovery in the case revealed it had acted in bad faith and had defamed Jon’s clients.

$3 Million Record Settlement – Wrongful Death Case

As lead counsel on behalf of the plaintiffs in a wrongful death lawsuit, Jon obtained a record settlement in excess of $3 million against Penske Truck Leasing and others in a product liability case involving a rental trailer that decoupled on the highway resulting in multiple fatalities.

$1.8 Million Damages Award – Negligent Entrustment

As lead trial counsel, Jon obtained a damages award of more than $1.8 million in a negligent entrustment case against the parents of a driver who killed a young wife and mother, believed to be the largest negligent entrustment damages award reported in Kansas.

Trial Verdict – Leads to New Missouri Rule of Civil Procedure

As lead trial and appellate counsel, Jon twice prevailed at trial, and succeeded on appeal, in the landmark case of Johnson v. McCullough, 306 S.W.3d 551 (Mo. Banc 2010).  After Jon obtained a unanimous verdict at trial, the adverse party appealed and the trial court ordered a new trial because a juror had failed to disclose during jury selection certain previous litigation experience.  On appeal, Jon persuaded the Missouri Supreme Court, en banc, to change a longstanding rule from prior precedents and to require that attorneys now must perform on-line searches during jury selection to determine whether prospective jurors have been involved in prior litigation.  As a result of the Johnson decision, the Court promulgated a new Missouri Rule of Civil Procedure, Rule 69.025 Juror Nondisclosure.  The Johnson decision topped Missouri Lawyer’s Weekly’s list of the “most important opinions” of 2010.  Following the Court’s decision, Jon prevailed again on retrial of the case under the new rule.

Substantial Settlements – Breach of Contract

As counsel on behalf of a corporate policyholder Jon obtained a substantial settlement in an amount twice the liability limits of an excess liability insurance policy in a case involving claims against the insurer for breach of contract, vexatious refusal to pay and bad faith.

As counsel on behalf of a corporate policyholder Jon obtained a substantial settlement against an insurer and its managing general underwriter (MGU) in a case involving claims against the insurer and MGU for underwriting errors and omissions, breach of contract and vexatious refusal to pay under a medical stop-loss excess insurance policy.

As counsel on behalf of the elderly beneficiary of a revocable trust, Jon obtained a substantial settlement in a case involving claims for breach of trust and breach of fiduciary duty against a large financial institution after the trust was substantially depleted by the beneficiary’s adult son.

Defense Success Against $100 Million Alleged Patent Infringement

As counsel on behalf of a food products manufacturer, Jon successfully defended a patent infringement lawsuit, which was resolved with no payment of money by his client, wherein the plaintiff (a large food products manufacturer) initially sought damages in excess of $100 million for alleged willful patent infringement.

Defense Success on Alleged Agreement Violation

As counsel on behalf of an individual investment advisor, Jon successfully tried and defended on appeal a case involving allegations of tortious interference, conversion and violation of a non-compete agreement in relation to investor accounts valued in excess of $40 million.

Medical Malpractice Settlements

As counsel on behalf of numerous physicians and other health care providers Jon has successfully resolved numerous medical malpractice cases by way of both trial and settlement. Jon also has represented a number of health care providers before their respective professional boards.

Plaintiff Success Against Pharmaceutical Manufacturers

As counsel on behalf of various plaintiffs injured as a result of taking dietary supplements containing Ephedra, Jon prosecuted and successfully resolved suits against several supplement manufacturers.

Notable Litigation

  • JUUL Labs, Inc., MDL No. 2913

    Wagstaff & Cartmell is involved in this MDL against JUUL Labs, Inc. Tom Cartmell has been appointed the Plaintiff’s Government Entity Liaison Counsel of the JUUL Labs Inc. MDL in the Northern District of California in front of the Honorable William H. Orrick.

  • $6.7 Million Plaintiff Verdict

    At the conclusion of trial, Jon Kieffer, Vanessa Gross and Adam Davis obtained a $6,723,021.00 damages award on behalf of the family of a young woman who had been killed in a two-vehicle collision. The case was filed by the surviving husband on behalf of himself and their three young children. The defendants in the case were the driver of the other vehicle, as well as the driver’s parents and thei

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Practice Areas

Other Practice Areas

  • Injury & Wrongful Death
  • Drug and Medical Devices
  • Nursing Home Injuries/Abuse
  • Trailer Sway/Trailer Decouplings
  • Business Disputes
  • Antitrust Litigation
  • Securities & Financial Fraud Litigation
  • Intellectual Property Litigation
  • White-Collar Crime and Complex Criminal Investigation

Prior Work

Federal Reserve System, Securities and Commercial Transactions


  • J.D., University of Kansas School of Law
    • Editorial Board, Kansas Law Review
    • Outstanding Student Trial Advocate
    • First Place, American Judges Foundation National Legal Writing Competition


  • B.A., University of Missouri – Kansas City
    • Cum laude