Expert investigators and screeners are experienced students of human behavior, and they've learned the area where job candidates will fudge the most when they write their resumes: education. Whether applicants think nobody will bother to check or that the information is hard to find is anybody's guess, but falsely claiming an educational degree is quite popular out there. And employers often assume that if an applicant is lying about one thing, there may be other areas worth looking into. (Curious about which area is second highest? Employment record.)

Aviation relies on human performance, and flight departments staffed by managers, flight crew, dispatchers, schedulers and technicians entrust their expensive aircraft to people who are selected and hired based on the expectation that they will perform to a required standard. Employers must exercise due diligence in hiring just as they do in financial transactions. The cost of employees is the number one or two cost in business today, so it makes little sense and, in the end, saves no money to hire people without knowing whether they are right for the job.

Small companies and flight operations may assume a professional background check is too expensive and try to conduct it themselves by calling references listed in a resume, but the results may not be as complete or efficient. Background screening is now a legally regulated and recognized profession with its own not-for-profit organizations that formulate the ethics members must follow.

The American Society for Industrial Security was founded in 1955 and later changed its name to ASIS International to reflect its global membership. Charlie LeBlanc, president of the security firm ASI Group, calls ASIS "the NBAA of the security world." The National Association of Professional Background Screeners was formed in 2003, and most reputable companies are members of one or both.

Do-it-yourselfers are also cautioned that a federal law, the Fair Credit Reporting Act, regulates the limits on ways an individual's past history can be examined. State laws vary but many are even stronger than the federal regulations, and you can find yourself wandering through a minefield.

Les Rosen, president and CEO of Employment Screening Resources, a number-one-rated firm in one survey of the field, says, "Basically, background screening in all industries underwent a dramatic increase after 9/11." Rosen also notes an increase in media attention to child molestation and a growth since the 1970s in verdicts that find negligent hiring practices and subsequent liability.

"If you hire a person who is unsafe, unfit, unqualified or dishonest, you may be found negligent," he says. Further, any employers filling high-risk occupations have a "duty of care in hiring to prevent foreseeable harmthe higher the risk, the higher the duty. We consider aviation high-risk."

As for the cost of background screening, it varies with the company doing it and the depth of investigation required by the employer. Rosen applies this rule of thumb: "An average background check is less than you pay an employee by 2 p.m. of their first day on the job." Some aviation jobs may run higher, to about $150 to $200 to conduct a background screening for a pilot applicant. LeBlanc, whose firm specializes in aviation, (it used to be affiliated with Air Routing, but became part of Medex in May 2008) also publishes international travel alerts, and he thinks a flight department is a unique situation because of its transient nature. Aviation people seem to move around a lot. He estimates that adding a credit check may cost the employer another $500.

The NAPBS document "Verifications Best Practices: What Clients Need to Know for Successful Outsourced Verifications" lists the areas of information provided by job applicants that screening firms verify including employment history, education history, references, earned credentials and licenses and military service. It also refers to background screening companies as consumer reporting agencies, or CRAs.

It would be a good move for prospective employers to obtain a copy of this advisory document, which is on the organization's web site. The highlights of its guidelines: