(415) 332-4262

Meet Our Mesothelioma Lawyers

Our mesothelioma attorneys are known across the nation for their expertise and success over the past 30 years in handling lawsuits for people with mesothelioma and other asbestos cancer disease. We have recovered hundreds of millions of dollars for our clients.

Experienced Mesothelioma Law Partners

When you are seeking compensation for exposure to asbestos, you deserve a competent and caring team of attorneys and investigative experts whom you trust. Clients have confidence in our law firm and trial lawyers due to a long track record in trial success, asbestos product identification, asbestos exposure investigation, and knowledge about mesothelioma treatments.

The lawyers, investigators, paralegals and administrative staff at Clapper, Patti, Schweizer & Mason have proven experience in litigating, trying and settling asbestos and mesothelioma cases over many years. They will work closely with you to deliver caring, prompt and comprehensive representation.


Jack C. Clapper, Founder

Jack C. ClapperAmong the first lawyers in California to devote a practice almost entirely to victims of mesothelioma and other asbestos-related diseases. He is recognized nationally as a pioneer in the field. A graduate of Hastings College of Law in San Francisco, he received his Juris Doctor degree in 1978.

In the 1960's, Mr. Clapper was a fighter pilot in the United States Air Force and served in combat in Vietnam.

He is a member of the American Trial Lawyers’ Association the California Association of Consumer attorneys, Trial Lawyers for Public Justice, San Francisco Trial Lawyers Association, among other professional organizations. He and the attorneys working with him have obtained substantial settlements and multi-million dollar verdicts.

Learn more and contact Jack Clapper »

Steven J. Patti

Steven J. PattiWas named one of Northern California’s “Super Lawyers” by Law & Politics magazine. He has spent most of his legal career representing injured workers and their families, with emphasis on mesothelioma and other asbestos cancer cases. An accomplished trial lawyer, he also works on all pre-trial phases of the cases handled by the firm.

Mr. Patti has represented plaintiffs in individual trials as well as in several consolidated actions involving multiple plaintiffs and defendants. He has tried several cases to verdicts in excess of a million dollars. He frequently makes presentations on asbestos litigation at national conferences of asbestos lawyers.

Mr. Patti is a 1992 graduate of the University of California, Hastings College of Law and received a bachelor’s degree from Indiana University, Bloomington. Mr. Patti is a member of the American Trial Lawyers’ Association, California Association of Consumer Attorneys, Trial Lawyers for Public Justice and San Francisco Trial Lawyers Association, among other professional organizations.

Learn more and contact Steven J. Patti »

Deborah F. Schweizer

Deborah F. Schweizer Graduate of the University of California, Berkeley, received her law degree from New York Law School in 1986. She has spent most of her career litigating complex cases including compensation for pollution cleanup, failed financial institutions, injuries from defective products and acts of sexual harassment and discrimination.

In the early 1990’s, Ms. Schweizer began to focus on clients who had been injured by exposure to asbestos. She has represented people diagnosed with mesothelioma and has tried numerous cases to verdict – including multiple verdicts in excess of a million dollars.

A member of the American Trial Lawyers Association and Consumer Attorneys of California, she is also a member of the Queen’s Bench.

Learn more and contact Deborah F. Schweizer »

John P. Mason

John P. Mason1997 graduate of San Francisco Law School, has devoted his career to victims of mesothelioma and other asbestos diseases. Involved in all aspects of litigation, he is best known for his ability to develop vital witness and documentary evidence supporting victims’ claims.

He is one of the foremost experts in product identification, that is, the gathering of evidence to prove which companies’ asbestos products were used at a given location. He supervises the investigative team at the firm and coordinates legal discovery. Mr. Mason is currently a member of the State Bar of California and the Consumer Attorneys of California.

Learn more and contact John P. Mason »