Firm History

In 1978 our firm was founded by Michael T. Thorsnes and Vincent J. Bartolotta Jr. Less than a year later we added a third partner, John F. “Mickey” McGuire.

In 1984, we moved to our present location comprising the 11th floor of the Manchester Financial Center at 2550 5th Avenue, San Diego.

Presently there are six partners including Kevin F. Quinn, Karen R. Frostrom, Ian C. Fusselman, and our newest partner, Brett J. Schreiber. Mike Thorsnes retired in 2002, but continues to be involved with the firm in an Of Counsel capacity.

From the start our firm has earned numerous commendations, among them designation in 1982 by American Lawyer Magazine as one of 20 outstanding new firms in the nation (less than 6 years old) and one of four from California. In 1983, TBM was selected as one of the seven leading firms in San Diego by San Diego Magazine.

In 2014 and 2015 the firm was recognized as a Best Lawyers® “Best Law Firms” by U.S. News & World Report and received the prestigious Tier One ranking for San Diego in the categories of Commercial Litigation; Litigation – Construction; Litigation – Real Estate; Mass Torts Litigation/Class Actions; Personal Injury Litigation – Plaintiffs and Product Liability Litigation – Plaintiffs. Since that time, all six partners, as well as our four associates, have had favorite success stories, none sweeter than those for which they have been recognized by peers in diverse legal fields ranging from construction defects to personal injury to medical malpractice to business litigation. A chronology of the firm includes such awards conferred with astonishing regularity upon Thorsnes Bartolotta McGuire partners as “Outstanding Trial Lawyer,” “Trial Lawyer of the Year,” and “Best Lawyers in America”.

TBM partners will tell you that every case they handle is important, but some of their cases have received more public attention than others. These include those which established important legal precedents, pioneered the use of technology, or, in terms of San Diego history, were defined by extraordinary public interest.


Holmes v. General Dynamics

Established tort liability for persons discharged for protesting wrongful conduct by an employer whether or not they blew the whistle on such conduct.


Shepard v. Cal Farmers Insurance

Established the requirement that a health insurer advise a policy holder that a disability leading to Medicare coverage would result in restricted private coverage.


Border Business Park v. The City of San Diego

The largest verdict against the City of San Diego ($132,000,000.00) for a breach of contract / inverse condemnation case. Causing the City to review it’s development agreement procedures and requirements.


Roman Catholic Bishop of San Diego v. Readers Digest

Secured $40,000,000 settlement on behalf of nationwide class of schools and school districts for improper monopolistic conduct relating to school fundraising programs.


Foodmaker v. Vons

Helped to create tougher food industry standards to protect the public against tainted meat.


Costarakis v. Nurshare

One of the first cases in California in which a substantial penalty was leveled against a health care provider whose employee abused an elderly patient.


Matsumoto v. Matsumoto

The first trial in California, and one of the first in the country, where a woman sued her husband for spousal abuse.


Colunga v. Hercules

Secured largest settlement ever in qui tam action where manufacturer of solid fuel nuclear tipped rockets falsified manufacturing and inspection records.


Baldwin et al v. Carlton Santee Corp.

Helped to establish legal standards in cases involving landslide subsidence.


Davis v. USAA

Established that an insurance company must notify a policy holder if a renewal results in a reduction in benefits.


County of San Diego v. Rancho Vista Del Mar (De La Fuente)

Secured the largest condemnation verdict in California.


Del Coronado Santee Townhomes Assoc. v. LAR Development/ D.G. & Associates

Revolutionized procedures for litigation of complex cases, reducing the court time by the use of our pioneering use technology for the instantaneous retrieval and presentation of evidence to a jury.

A smaller triumph, which ultimately reaped unexpectedly large results, came in Riviera v. Ronaghy.

The client was so gratified by the award won in a burn and injury case that he asked our partners to donate $10,000 of it to charity. We happily complied, deciding to use the money to repair Primo Tapia, an orphanage in Tijuana, Mexico. After learning of the donation, a second orphanage, La Gloria, asked us for help with similar repairs. We agreed, and also sponsored a Christmas party for children in the area. At the party, our partners learned about the work of Clinica del Niños (Children’s Clinic) in treating children of impoverished families for routine ailments and referring them to hospitals for more serious problems. There was a chemistry between Clinica del Ninos and the TBM firm, with attorneys, paralegals, secretaries, law clerks and data processors elected to participate in a payroll deduction and matching grant program to underwrite the year-round costs of keeping the clinic open. TBM-sponsored Christmas parties have become an annual tradition at the clinic, located in Rosarita Beach. For more detailed information see Commitment to the Community Beyond the Courtroom.

A few of the cases that were the subject of extraordinary public interest while being litigated include:

“We work hard to improve the quality of life for our clients and then we enjoy sharing the rewards of our legal practice by improving the quality of life in our community. We take as much pride in our giving as we do in our courtroom work.”

– John F. “Mickey” McGuire

Civil Trial Lawyers