.

G. Mark Thompson

President & CEO

Chairman, Executive Committee

GMThompson@mdwcg.com

Portrait of G. Mark Thompson

As President and CEO of Marshall Dennehey, Mark is responsible for the day-to-day management and business strategy of the firm which consists of 500 attorneys operating out of 19 offices throughout Pennsylvania, New York, New Jersey, Connecticut, Delaware, Ohio and Florida. He was elected to the position in December of 2017 after serving more than three years on the Executive Committee and a decade on the Board of Directors. He succeeded Tom Brophy who served in the role for 13 years.

Mark is joined by a management team comprised of two other senior executives, a Board of Directors, managing attorneys from every office, practice group supervisors, administrative directors and over 1,000 employees who combine their talents to develop and implement the strategies and achieve the objectives of the firm and its clients.

Prior to moving to the firm's Philadelphia headquarters in 2014, Mark also served as the regional managing attorney for its four Florida offices. A Florida native, it was there he built a reputation as a "go to" attorney advising Fortune 500 clients in high profile, high exposure and often crisis  situations. During his career he has handled matters that attracted international media attention, are the subject of books, a documentary film and in one instance a hearing before the US House of Representatives in Washington DC, at which Mark represented one of the corporations testifying.

Mark has more than 30 years of experience in the legal profession, is rated AV Preeminent by Martindale Hubble, was recognized in 2006, 2007, 2013 and 2014 as a Florida Super Lawyer and in 2012 as one of Florida's Legal Elite by Florida Trend magazine. He is admitted to practice before the Florida Supreme Court, the United States Court of Appeals for the Eleventh Circuit and the United States District Court for the Middle District of Florida. He has tried cases in county, circuit, and federal courts and argued before the District Courts of Appeal. In 2012 he also became licensed to practice in Pennsylvania.

Prior to attending law school, Mark spent two years working as an insurance adjuster. The experience continues to inform his understanding of the critical needs of claims professionals.

His civic activities include serving on the Board of Directors of Christian Legal Clinics of Philadelphia, a legal aid organization assisting the disadvantaged, whose north Philadelphia clinic was started and is staffed every month by Mark and his colleagues from Marshall Dennehey. Mark also has served on the Grants Committee of the Philadelphia Bar Foundation.

    • Cumberland School of Law (J.D., 1989)
    • University of Florida (B.A., 1984)
    • Florida, 1989
    • U.S. District Court Middle District of Florida, 1990
    • U.S. Court of Appeals 11th Circuit, 1998
    • Pennsylvania, 2012
    • Supreme Court of the United States
    • AV® Preeminent™ by Martindale-Hubbell®
    • Florida Super Lawyers (2006-2007, 2013-2014)
    • Florida Trend Magazine's Florida Legal Elite, 2012
    • Pennsylvania Super Lawyers (2018-2022)
    • Claims & Litigation Management Alliance (CLM)
    • Defense Research Institute
    • International Amusement & Leisure Defense Association
    • International Association of Amusement Parks and Attractions (IAAPA)
    • Orange County Bar Association
    • The Best Offense is a Good Defense: Managing Liability Claims in Today's Litigious Environment, Business Insurance Webinar, August 12, 2015
    • The Claim Management Link: Interplay Between Risk Tolerance, Operational Structure, Litigation and Claim Outcomes, CLM Annual Conference, March 2015
    • Florida Premises Liability - Investigation and Defense
    • Florida Liquor Liability
    • Spoliation of Evidence
    • Defended a corporation and obtained summary judgments in multiple federal lawsuits alleging sponsorship, production, distribution and sale of videos depicting plaintiffs' underage participation in various spring break contests.
    • Defended a manufacturer and obtained satisfactory confidential resolution of claims brought by 51 factory employees alleging toxic exposure.
    • Defended a state agency and obtained defense verdict in wrongful death trial alleging inadequate traffic control.
    • Defended a major insurer and obtained defense verdict in trial brought by owner of an oddities museum whose collection and building was completely destroyed by fire.
    • Defended a tourist destination and obtained summary judgment in a negligence action brought by a contracted performer rendered quadriplegic as a result of an accident during a gymnastic slam dunk exhibition.
    • Defended a company and obtained defense verdict on appeal in lawsuit alleging bottle "exploded" while being handled by plaintiff.
    • Defended a tourist destination and obtained defense verdict in trial alleging inadequate slip resistance of drainage grates.
    • Defended and settled numerous lawsuits involving tractor trailer rollovers allegedly caused by improper loading of cargo.
    • For nearly 20 years, defended theme parks and tourist destinations throughout Florida in hundreds of cases involving amusement rides, wild animals, negligent security, E-coli outbreaks, slip and falls, defamation, food poisoning, false imprisonment and matters of intellectual property.
    • Anheuser-Busch, Inc. v. Lenz, 669 So.2d 271 (Fla. 5th DCA 1996)
    • Becton v. Metal Container Corp., 856 So.2d 982 (Fla. 1st DCA 2003)
    • Jordan v. Sea World of Florida, Inc., 938 So.2d 991 (Fla. 5th DCA 2006)
    • Badillo v. Anheuser-Busch, 19 Fla. L. Weekly Fed. D 641 (M.D. Fla. 2006)

Thought Leadership

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Media Commentary

G. Mark Thompson Quoted in The American Lawyer Article on Staffing in Defense Industry

August 15, 2024

Media Commentary

Marshall Dennehey President & CEO Featured on Cover of Best's Review

May 1, 2024

Marshall Dennehey President & CEO G. Mark Thompson was featured on the cover of the May 2024 issue of Best's Review and quoted in the article, "For the Defense."

News

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Firm Highlights

Result

No-Cause Jury Verdict Secured in Wrongful Death Trial

We successfully obtained a no-cause jury verdict in a 13-day wrongful death trial. The decedent, a 59-year-old man, was admitted to the emergency room on February 15, 2019, with complaints of abdominal pain, decreased appetite, and constipation, despite the use of laxatives. The patient did not complain of any nausea, vomiting, or diarrhea. He had a significant medical history including diabetes, hypertension, prior coronary artery stenting, morbid obesity (with past gastric bypass surgery), longstanding ventral hernia, and back pain. A CT scan revealed multiple hernias and a potential closed-loop bowel obstruction, leading to a surgery consultation. Our client, an emergency general surgeon, interpreted that the patient did not have a closed loop or any significant obstruction and recommended non-surgical management. The patient was approved to have clear liquids, and had a vomiting incident shortly after, but our client was not notified. The patient was returned to NPO status, and after improving overnight, he was returned to “clears” and additional medical and renal consults were ordered. Our client did not receive any communications from the residents/nurses of any changes in the patient’s condition. On February 18, 2019, two rapid responses were called due to increased heart rate and vomiting. It is believed that the vomiting resulted in aspiration, causing sepsis, ultimately leading to the patient’s death. During the trial, the plaintiff’s sole medical expert highlighted imaging on the wrong hernia, which called into question all of his opinions in the case. We made key objections related to the expert testimony, limiting what the allegations were, and preventing new allegations from being made. After approximately two and a half hours of deliberating, the jury returned a no-cause verdict. 

Casey Alan Coyle Joins Marshall Dennehey's PA Appellate Practice as a Shareholder in Harrisburg and Philadelphia

News

Marshall Dennehey Expands Leading Pennsylvania Appellate Practice With Addition of Shareholder Casey Coyle

Portrait of Carolyn Schweizer, with text below: Philadelphia Office Managing Attorney

News

Marshall Dennehey Names Carolyn Schweizer New Philadelphia Office Managing Attorney

Unanimous Verdict Obtained in a Medical Malpractice Matter in Bergen County, New Jersey

Result

Unanimous Verdict Obtained in a Medical Malpractice Matter in Bergen County, New Jersey

Result

Summary Judgment Secured, Preserving $750,000 in Coverage for Insured in Major Trucking Liability Dispute

Ray Freudiger and Michael A. Roberts (both of Cincinnati) successfully obtained summary judgment on behalf of their client in a coverage dispute arising from a May 19, 2022, motor vehicle accident. A permissive driver operated a box truck for an interstate trucking company and caused severe injuries to two tort victims. Prior to the accident, the insured had procured a commercial auto policy for the trucking company with stated limits of $1,000,000. Following the accident, the insurer initiated a declaratory judgment action asserting that only reduced bodily injury limits of $25,000/$50,000 applied and later counterclaimed, alleging it would not have insured the driver had he been properly submitted for approval under the policy. After extensive discovery, briefing, and oral argument, the court rejected the insurer’s attempt to shift responsibility for the $750,000 in coverage it was legally required to provide for permissive drivers under Ohio law, granting summary judgment in favor of the insured and preserving $750,000 in liability exposure.

blue facade of a hospital sign against blue sky

Result

Defense Verdict in Complex Medical Malpractice Trial

Congratulations to our 2026 Florida Super Lawyers & Rising Stars: Elizabeth Ferguson, A.C. Nash, Taylor Naughton, Sophia Philor, Amara Rodriguez

News

Marshall Dennehey Announces 2026 Florida Super Lawyers & Florida Rising Stars

Thought Leadership

Vendor Cyber Attack Compromises PII of More Than 3 Million Hunting and Fishing License Holders in Texas

The Texas Parks & Wildlife Department (TPWD) announced earlier this month that one of its vendors which handles the sale of state hunting and fishing licenses was the victim of a cybersecurity attack. The threat actor appears to have exfiltrated personal driver’s license information, passport numbers, email addresses, phone numbers and addresses of over 3 million hunting and fishing license holders.  The State Parks Department advised that the attack did not compromise social security numbers, dates of birth or financial information. Texas Cyber Command, the state’s new cybersecurity authority formed to protect critical infrastructure and coordinate threat responses across state and local government, reportedly assisted in detecting and containing the attack. TPWD has already set up free credit monitoring for those impacted through Kroll.  According to press reports, no specific group has yet been identified as the perpetrator of the theft. TPWD also advised that business has not been interrupted and license sales were continuing. This incident once again demonstrates that cybersecurity is only as strong as the weakest link in the supply chain. Businesses must prioritize security across their own environments and those of their vendors and contractors as well.

Thought Leadership

Legal Update for Special Education Law: Recent Positive Outcomes From the Group

Hearing Officer Confirms District Acted Appropriately Under IDEA and Section 504 William J. McPartland (Scranton) obtained a finding in favor of our client, a school district, on all issues following a due process hearing. The parent had filed a due process complaint alleging that the school district had breached its child find duty under the IDEA and Section 504, that the school district had discriminated against the student on the basis of disability in violation of Section 504, and that the school district had denied a free and appropriate public education to the student both by developing inadequate IEPs and via an actionable procedural violation.  Specifically, the student had received a Section 504 evaluation in October 2023, after a number of behavioral infractions culminating in a fight in September 2023, was identified as having anxiety and a sleep disorder, and received appropriate Section 504 accommodations. The student had never previously demonstrated signs of a learning disability, and the parent denied the school district permission to evaluate the student for special education needs in November 2023, and January 2024. The parent granted the district permission to evaluate the student in October 2024, after a private psychologist diagnosed the student with Attention Deficit Hyperactivity Disorder, possible Oppositional Defiance Disorder, a learning disorder, and anxiety. The school district issued a special education evaluation report in December 2024, finding that the student had an emotional disturbance and other health impairment, and an IEP providing an itinerant level of emotional support, as well as instruction in academics and social skills, was issued in January 2025, and amended in February, March, and April 2025. The student withdrew from the school district in April 2025, to attend a cyber charter school. The hearing officer determined that the school district had not violated its child find duty to the student in violation of either the IDEA or Section 504 where the district developed a Section 504 plan for the student within a month and a half of the parent’s first request for a Section 504 evaluation and where the parent repeatedly denied consent to conduct an IDEA evaluation of the student. The hearing officer noted that the student’s sporadic record of behavioral infractions prior to September 2023, did not suggest that the student had a disability prior to the parent’s initial request for an evaluation. The hearing officer further determined that no evidence had been produced to suggest that the student was discriminated against on the basis of disability in violation of Section 504. Additionally, the hearing officer determined that the IEP offered to the student was substantively adequate and that, to the extent the social and emotional programming offered by the school district was not received by the student, this resulted from the parent’s refusal to accept the same. The hearing officer finally determined that the school district did not commit an actionable procedural violation by delaying development of an IEP for the student where the parent repeatedly denied consent to evaluate the student. Court Dismisses Three of Four Claims Against School District Christopher J. Conrad and Daniel P. McGannon (Harrisburg) achieved a significant early victory on behalf of a school district client in. The team successfully obtained dismissal of three of the four claims asserted in the plaintiff’s amended complaint. The former district superintendent brought multiple claims arising out of his alleged “forced resignation,” including age discrimination under the ADEA, a Section 1983 Equal Protection claim, a Pennsylvania Whistleblower claim, and breach of contract. On behalf of the district, the defense team moved to dismiss the complaint in part, arguing: The plaintiff failed to plead sufficient facts to support a prima facie case of age discrimination. The equal protection claim was barred because the ADEA provides the exclusive federal remedy for age-based employment claims. The breach of contract claim could not stand because the underlying employment agreement had expired prior to the alleged breach. The court agreed, dismissing the ADEA, equal protection, and breach of contract claims in their entirety. As a result, only a single claim under the Pennsylvania Whistleblower Law remains pending. This outcome substantially narrows the scope of the litigation and positions the client for a more efficient defense moving forward.

Thought Leadership

Featured Conversations... Key Takeaways from A.M. Best’s Webinar on the Misuse Defense in Product Liability Claims, Featuring Michael Salvati

Michael Salvati, shareholder in our Philadelphia office, was a panelist for the April A.M. Best webinar, “The Misuse Defense: Strategic Approaches to Defending Product Liability Claims for Insurers.” During the program, Michael and his fellow panelists offered practical, jurisdiction‑specific guidance on how misuse and failure‑to‑warn theories intersect in modern product liability litigation. Michael emphasized the unique challenges these claims present—particularly in states like Pennsylvania, where evidentiary rules diverge sharply from those applied in many other jurisdictions. Failure to Warn as the “Flip Side” of Misuse Salvati explained that failure‑to‑warn allegations often arise as a direct counter to a misuse defense. As he noted, “If our misuse defense is that the plaintiff didn't use a product properly or safely, then the failure to warn claim is that we didn't tell them how to use it properly.” He emphasized that these claims can stem from either the absence of warnings or criticisms of existing warnings, such as insufficient specificity or lack of clarity about risks. Pennsylvania’s Unique Evidentiary Landscape One of Salvati’s most notable points was the stark difference in how Pennsylvania treats evidence of compliance with industry standards. He highlighted that Pennsylvania is “one of the only states…where that evidence is not admissible” in strict liability cases. Manufacturers cannot rely on compliance with ANSI, UL, ISO, or even federal safety standards to defend the product against a strict liability claim—because the focus is solely on the product itself, not the manufacturer’s conduct. Salvati acknowledged the challenge this creates for defense counsel and clients who expect such compliance to carry weight. Understanding the Three Defect Theories Salvati also walked through the three primary defect theories recognized in many jurisdictions: - Design defect – a flaw in the product’s intended design - Manufacturing defect – a deviation affecting a specific unit - Failure to warn – inadequate instructions or warnings He noted that warnings claims are increasingly significant and sometimes stand alone when design or manufacturing theories are weak. As he put it, plaintiffs often default to warnings claims because “the default position seems to be, ‘If I got hurt, there must be something wrong.’” Warranties and State‑by‑State Variations Salvati addressed how breach‑of‑warranty claims fit into the broader framework, explaining that implied warranties—such as merchantability—often overlap with strict liability in Pennsylvania. He emphasized the importance of understanding local nuances, as warranty law and admissibility rules vary widely across states. Looking Ahead: The Growing Importance of Warnings In his closing remarks, Salvati stressed that warnings should never be treated as an afterthought in product liability defense. He observed that warnings‑only claims are becoming more common and urged manufacturers and insurers to continually evaluate the clarity and completeness of their instructions and warnings. His takeaway: “We should always be talking about what are the instructions that come with our products…to bolster a misuse defense.” Listen to the complete webinar here: https://www3.ambest.com/conferences/events/eventregister.aspx?event_id=WEB1074.