What shows up on a background check?

It depends on the Background check.

There are several types: security clearance, basic check for an apartment, gun purchases, and some others.

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That totally depends on the type of background check being conducted.

If we talk about the criminal cases, the things shown during background checks are those who are convicted or charged with misdemeanors, felony, sexual offenses, and violations of parole. The law also permits to check for traffic violations, arrest records, violations against provision, and the list continues!