Andrew Walsh

Andrew Walsh represents clients facing high-stakes environmental litigation, media and entertainment litigation, federal and state investigations, white collar criminal actions, and civil business disputes. He has represented Fortune 500 companies, governments, and individuals in a variety of industries, including environmental services, technology, and media and entertainment. In 2015 and 2016, he was named a “Rising Star” by Super Lawyersmagazine.

Across multiple areas of practice, Mr. Walsh brings his skills as a litigator and counselor to clients entangled in complex civil and criminal matters. In every case, he works to gain a thorough knowledge of his client’s organization or business, creating a platform from which to successfully challenge and thwart pending allegations. In this way, he successfully averted felony charges against a subsidiary of the nation’s largest environmental services provider, by unraveling the substance of a years-long criminal investigation and 14-count felony indictment — including allegations of conspiracy and false statements — to reveal government weaknesses, overreach, and misconduct. He also used his expertise in corporate parent and subsidiary relationships to avert the imposition of any liability on the parent company for the alleged acts of its subsidiary. At every turn, he forced the government to its proof, resulting in no disposition of any kind for the parent company.

Most recently, Mr. Walsh was on the trial team that successfully obtained a complete dismissal after the first day of trial on behalf of Sumner Redstone, chairman emeritus of CBS and Viacom. Mr. Walsh continues to represent Mr. Redstone in related litigation. In other litigation, Mr. Walsh currently represents the Navajo Nation with regard to exposure of its people, water, and lands to contaminants from the August 2015 Gold King Mine spill. In this capacity, Mr. Walsh protects and advances the Nation’s interests through all means, interacting with federal regulators and policymakers, such as the Environmental Protection Agency. [See “Navajo Nation Sues EPA” in Law360 , and “Navajo Nation Sues EPA over Toxic Mine Spill” on]

A key member of the firm’s environmental litigation team, Mr. Walsh is involved in all aspects of the practice, counseling and guiding clients through complex regulatory and compliance matters. He has particular experience with regard to massive contaminant releases, water quality standards, resource recovery, and other issues that fall under the Clean Water Act and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

Mr. Walsh is also an active pro bono attorney. He recently prevailed at three trials, securing permanent restraining orders for victims of domestic abuse, as well as orders of full physical and legal custody of the victims’ young children. Past work includes representing families in adoption proceedings, and representing the Animal Legal Defense Fund.

Prior to joining Hueston Hennigan LLP at its inception, Mr. Walsh was an associate at Irell & Manella LLP in Los Angeles, where he focused on environmental litigation, white collar criminal defense, and civil business disputes.


  • Trial counsel for Sumner Redstone, chairman emeritus of Viacom and CBS, in defense of mental competency case, obtaining a complete dismissal after the first day of trial. [See “Judge dismisses mental competency case against Sumner Redstone,” in the Los Angeles Times ; “Ex-Viacom Chair Beats Competency Suit,” in Law360 .]
  • Represents Navajo Nation in matters related to the Gold King Mine waste-water disaster. [See “Navajo Nation Sues EPA over Gold King Mine Spill,” in Law360 .]
  • Achieved dismissal of all felony charges against a subsidiary of a Fortune 250 company in a criminal matter involving allegations of conspiracy, false statements, and violations of the Clean Water Act. [See “Hawaii Waste Co., DOJ Reach Deal Over Storm Runoff” in Law360 .]
  • Represented a communications company in an action for the misappropriation of trade secrets, resulting in a favorable settlement.
  • Represented a technology company in a patent infringement action concerning DVR technology, resulting in a favorable settlement.
  • Represented an individual in a criminal investigation into alleged violations of the Food, Drug, and Cosmetic Act.
  • Represented a biotechnology company in a complex breach of contract action concerning the payment of patent royalties, resulting in a favorable settlement.

Andrew Walsh

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Loyola Law School (J.D., 2010) summa cum laude; Sayre Macneil Scholar; Order of the Coif; St. Thomas More Law Honor Society

UCLA (B.A., Geography and Environmental Studies, 2004) summa cum laude; college honors


California 2010

U.S. District Court Central District of California