A handful of skilled private detectives/investigators work with defense attorneys on capital punishment and other criminal defense cases. Many are insurance investigators who investigate suspicious claims. Before the advent of no-fault divorce, many private investigators were hired to search out evidence of adultery or other conduct within marriage to establish grounds for a divorce. Despite the lack of legal necessity for such evidence in many jurisdictions, according to press reports collecting evidence of adultery or other "bad behaviour" by spouses and partners is still one of the most profitable activities investigators undertake, as the stakes being fought over now are child custody, alimony, or marital property disputes.
Most jurisdictions require a clean criminal record at the licensing application entry point. When a board of directors exists, it will review an applicant's appeal to determine whether the board can approve the application based on the elapsed amount of time since the last offence was recorded. The board of appeal may approve an application based on good conduct within the last five to ten years.
Private investigators can also be used to perform due diligence for an investor who may be considering investing money with an investment group, fund manager or other high-risk business or investment venture. This could serve to help the prospective investor avoid being the victim of a fraud or Ponzi scheme. By hiring a licensed and experienced investigator, they could unearth information that the investment is risky and or that the investor has suspicious red flags in his or her background. This is called investigative due diligence, and is becoming much more prevalent in the 21st century with the public reports of large-scale Ponzi schemes and fraudulent investment vehicles such as Madoff, Stanford, Petters, Rothstein and the hundreds of others reported by the SEC and other law-enforcement agencies.