Final answer:
Job reference checks should be conducted before a conditional offer of employment, while other checks like criminal and credit checks are done afterward. It's illegal to ask about a candidate’s birth state during an interview in the U.S.
Step-by-step explanation:
Among the types of background checks listed, job reference checks should generally be done before a conditional offer of employment has been made. This involves contacting previous employers or colleagues to verify a candidate's work history and qualifications. On the other hand, criminal background checks and credit checks are typically done after an offer has been made, contingent upon successful completion of these checks. It’s important to comply with all legal requirements, including the Fair Credit Reporting Act (FCRA), when performing these checks. Social media checks are also commonly conducted, but they must be done carefully to avoid discrimination or invasion of privacy. Regarding the question on illegal interview questions in the United States, asking candidates about their birth state is not permitted as it could lead to discrimination based on national origin, which is protected under Title VII of the Civil Rights Act of 1964. Questions about education, driver's licenses (when relevant to the job), and salary expectations are generally acceptable.