They ordered an investigation led by investigators not affiliated with the company. These detectives include amateurs, private investigators and professional policemen. The investigation involved at least 80 Swiss investigators. The researchers found financial relationships among industry, scientific investigators, and academic institutions widespread. Serpico believed his partners knew about his secret meetings with police investigators. All of these investigations are conducted by Diversion Investigators (DIs). Not all federal criminal investigators are called special agents. Intel reported that it was cooperating with investigators. Each episode had a new 'cast', including interviews with witnesses, investigators, and forensic scientists. Critical switches identified by investigators were inhibited. The episode featured interviews from witnesses and accident investigators and recreations of the crash. This evidence is collected by crime scene investigators (CSIs) and law enforcement. Another plot involving Bauchi alleged by US investigators involved Heathrow airport. It featured interviews with witnesses, the family, and investigators. Clinical trials are classified by the research objective created by the investigators.