Answered by Steve, Hiring Expert at Caterpillar Inc., on Friday, January 9, 2015
For most employers, it is an issue of liability. For example, if a company has a position open that requires someone to drive a vehicle, that company is likely not going to be interested in someone with a history of driving under the influence or reckless driving. This would place that company at risk, so they avoid these situations. Another example would be for someone who has been convicted of theft. If they are being considered for a job in which they would would have access to company funds or other assets, the company would generally shy away from them because of the associated risk.
What generally causes the most issues for people with a criminal history is that candidate's failure to disclose their history to a potential employer. There are many cases when someoene goes through the interview process and is offered a job, only to have that job offer rescinded because something comes up on their background check that they did not disclose to the company. Even if it is something minor that is not related to the job, the fact that they did not disclose it creates a bigger issue because they are falsifying their background.