Three services dominate the highly diversified field of security services: security guard services, private detective services, and alarm system contract services. A 1976 report on private security determined that State regulation is the most appropriate method for controlling the security field. Questionnaires were sent to each of the 50 States, requesting information on regulation of the 3 primary security services. Forty-seven States responded. The survey found that 33 responding States regulate security contract and guard services. The same number also regulate private investigators. Alarm system contractors face regulation in only eight States. The most common substantive requirement for licensure is lack of a felony conviction. Other common requirements include U.S. citizenship, a minimum age, experience in a related field, and successful completion of a written examination. In most instances, grounds for revocation of license were similar to grounds for denial of license. Almost all arrest regulations were in effect in 1976. Most subsequent activity has dealt with alarm systems. Industry leaders currently advocate training programs and industry certification to supplant and/or supplement regulation. The report includes an exhibit of requirements by State and a listing of the addresses of State regulating agencies.