Use Private Investigators
In the movies, you'll often see someone faking whiplash after a car accident. After the person gives a false statement to authorities, the movie cuts to the person at home -- sans the big foam collar -- engaging in an athletic endeavor that would be impossible if he or she really had whiplash. Next scene: A private investigator, hiding in the bushes, snaps a photo of the "victim" and takes off.
That's not just the stuff of Hollywood. Private investigators do stake out insurance claimants at times for just such reasons. They also use less dramatic tactics to uncover fraud, such as researching claimants' backgrounds through perusing criminal records, interviewing claimants and any witnesses, inspecting pertinent sites, etc. Investigators may also consult with the insurer's legal counsel and serve as expert witnesses in court. While some private investigators are hired by insurance companies on a freelance basis, insurers also hire in-house PIs, often selecting those with backgrounds in law enforcement and private investigation [source: Bureau of Labor Statistics].