Mathew L. Larsen

Mat is a trial lawyer and experienced litigator who handles cases from initiation through trial and appeal. Mat has significant experience defending complex cases and class action matters in state and federal courts around the country. Recently, he was trial counsel in a California state court action on behalf of a client whose product plaintiff claimed caused his Non-Hodgkin’s lymphoma. Plaintiff asked the jury to award $100 million in compensatory damages and $500 million in punitive damages. After deliberating three hours, the jury returned a complete defense verdict. In spring 2026, Mat was one of the trial counsel for a client’s first cosmetic talc trial in Los Angeles County. The case resolved for nuisance value after opening statements. Mat is routinely hired as trial counsel to handle cases in different jurisdictions around the country, and has been especially engaged in California case workup and trials over the past several years.  

Over the past decade, his practice has focused primarily on defending companies in toxic tort, product liability and environmental cases. He has worked closely with other outside law firms to develop and implement creative litigation strategies. Mat’s experience in a variety of complex, technical cases allows him to develop successful case strategies, including strategies for combating expert testimony.

Mat has represented chemical, energy, pipeline and engineering companies in claims involving chemical exposure, groundwater and soil contamination. He is experienced defending statutory claims brought under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the Resource Conservation and Recovery Act (RCRA), Clean Water Act (CWA), state environmental statutes, as well as common law claims such as nuisance, negligence and trespass. 

Some of Mat’s other experience includes:

• defending a national energy company, including in a month-long trial, against alleged responsibility for and cleanup of groundwater in a case involving environmental, contractual and common law claims;
• defending an industrial manufacturing company in several asbestos cases filed in different jurisdictions around the country; 
• defending a sand-mining company against alleged property devaluation and personal injury claims in a case attracting national media attention;
• defending an international engineering firm against soil contamination allegations and environmental, personal-injury and property-devaluation claims in a high-profile litigation attracting national media attention;
• arguing before the Missouri Air Conservation Commission and defeating class certification in in an odor nuisance case for a renewable fuels company; 
• defending the rights of a city to expand its sewer and water services, where he secured positive outcomes in a federal district court jury trial and on appeal to the Eighth Circuit. Pub. Water Supply Dist. No. 3 of Laclede County, Mo. v. City of Lebanon, Mo., 605 F.3d 511 (8th Cir. 2010);
• defending an international pet care provider in litigation brought by former employees claiming injury due to harmful chemical exposure.

Mat is also adept at handling class actions and lawsuits involving alleged violations of consumer statutes. He defended a national healthcare company in a class action against twelve of their nursing homes, employees and affiliated companies. The class action involved contractual, deceptive trade practice and state statutory claims based on allegations that they failed to provide sufficient direct-care staff to meet the needs of the residents. Mat assisted with the jury trial of a Kansas multidistrict litigation proceeding where plaintiffs alleged violations of the Kansas Consumer Protection Act for failure to disclose the temperatures of gasoline and diesel fuel. The jury returned a defense verdict, and the claims against Mat’s clients in the remaining states were subsequently dismissed.

Mat has also assisted clients with environmental audits and regulatory compliance, air and water permitting issues before state and federal agencies. He helps clients navigate open records and open meetings laws, and he has worked with government agencies conducting endangered species and cultural resource surveys for major public construction projects.