Mr. De Haas was born in Cleveland, Ohio and attended the University of Southern California receiving a B.A. in Psychology in 1963. Thereafter he attended the University of California, Hastings College of Law receiving a J.D. in 1966.
He spent two years as a prosecutor in criminal cases for the Los Angeles City Attorney's Office where he was then selected, because of his trial results, to the Civil Section of the City Attorney's Office, where he remained for three years defending the city in large civil exposure cases both in state and federal courts. In 1971 he joined La Follette Johnson where he became a named partner in 1976. Currently he is the president and senior trial attorney of the firm. Mr. De Haas has tried in excess of 300 jury trials, including over 150 medical malpractice cases. He has also tried multiple administrative hearings representing physicians before the California Medical Board. His litigation exposure consists of jury trials, arbitration, and cases venued both in state and federal courts. Mr. De Haas has argued cases in the appellate court of the State of California and the 9th Circuit Federal Court. He has written multiple appellate briefs for cases in the State of California, federal courts, and the United States Supreme Court.
In 2001 Mr. De Haas was the President of the Los Angeles Chapter of the American Board of Trial Advocates (ABOTA). He holds the rank of Diplomat, and is a member of the Executive Committee of the Los Angeles Chapter of ABOTA and past Member of the National Executive Committee of ABOTA. Mr. De Haas is also a recipient of the ABOTA Lee Wenzel Civility Award for 1999.
He is a fellow of the American College of Trial Lawyers of which entry is by invitation only and is limited to the top 1% of lawyers licensed to practice in the State of California, as selection is limited to the "best lawyers" in the state. He is also a fellow of the International Academy of Trial Lawyers which is limited to 500 attorneys in the United States. Mr. De Haas is also rated "AV" by Martindale-Hubbell.
Mr. De Haas was elected to the California Medical Legal Committee which is limited to twenty four senior medical malpractice attorneys from Southern California. He is the past editor of the Emergency Medical Legal Digest and was appointed as a special arbitrator by the Los Angeles Superior Court. He has been a member of the Los Angeles County Bar Association and the Association of Southern California Defense Counsel, where he also served on the Board of Directors.
He has been a lecturer for the National Institute of Trial Advocacy, the Association of Southern California Defense Counsel, Masters in Trial programs for ABOTA, Catholic Healthcare West, St. Paul Insurance Company, Daniel Freeman Memorial Hospital, St. Francis Medical Center, Sutter/Alta Bates Summit Medical Center, and Cooperative of American Physicians. Mr. De Haas is also on the faculty to teach at the Jack Daniels Trial School for ABOTA.
In 2005 Mr. De Haas successfully defended a medical malpractice case which was selected by the Los Angeles Daily Journal as the most significant defense verdict for 2005 in medical malpractice litigation for California. He has been designated as one of Southern California's Super Lawyers for 2006, 2007, 2008, 2009, 2010 and 2011 by Law and Politics. Mr. De Haas was most recently nominated as the 2013 Trial Lawyer of the Year by the Los Angeles chapter of ABOTA.